Positive resist composition

ABSTRACT

A positive resist composition comprising:  
     (A) a fluorine group-containing resin having: a structure wherein at least one of the main chain and the side chain of the polymer skeleton has at least one fluorine atom; and having a group capable of decomposing under the action of an acid to increase the solubility in an alkali developer;  
     (B) a compound capable of generating an acid upon irradiation with one of actinic ray and radiation, and  
     (C) a surfactant containing at least one of a silicon atom and a fluorine atom.

FIELD OF THE INVENTION

[0001] The present invention relate to a positive resist compositionsuitable for use in the microlithography process in the production ofVLSI or high-capacity microchip, or in other photo-fabricationprocesses. More specifically, the present invention relates to apositive resist composition capable of forming a highly definite patternusing a vacuum ultraviolet ray of 160 nm or less.

BACKGROUND OF THE INVENTION

[0002] The integration degree of integrated circuits is more and moreintensified and in the production of a semiconductor substrate of VLSI,an ultrafine pattern comprising lines having q width of quarter-micronor less must be processed. For achieving refinement of a pattern, meansof using an exposure light source having a shorter wavelength in theformation of a resist pattern is known.

[0003] For example, in the production of a semiconductor device havingan integration degree of up to 64 M bits, the i-line (365 nm) of ahigh-pressure mercury lamp has been heretofore used as the light sourceuntil today. For the positive resist respondent to this light source, alarge number of compositions comprising a novolak resin and anaphthoquinone diazide compound as a photosensitive material have beendeveloped and succeeded in giving a satisfactory result in theprocessing of lines having a width of about 0.3 μm or more. In theproduction of a semiconductor device having an integration degree of 256M-bits or more, a KrF excimer laser ray (248 nm) is employed as theexposure light source in place of the i-line.

[0004] Recently, for producing a semiconductor having an integrationdegree of 1 G-bit or more, an ArF excimer laser ray (193 nm) which is alight source having a short wavelength is used. Furthermore, use of anF₂ excimer laser ray (157 nm) is being studied for forming a pattern of0.1 μm or less.

[0005] To cope with this tendency toward shorter wavelength of the lightsource, the resist material is greatly changed in its constituentcomponents and chemical structure. More specifically, conventionalresists comprising a novolak resin and a naphthoquinonediazide compoundhave large absorption in the far ultraviolet region at 248 nm andtherefore, the ray may fail in reaching the resist bottom to asufficient depth, as a result, only a tapered pattern and lowsensitivity is obtained.

[0006] In order to solve this problem, a so-called chemicalamplification-type resist, that is, a composition mainly comprising aresin having a basic skeleton of poly(hydroxy-styrene) which shows smallabsorption in the region of 248 nm and is protected with anacid-decomposable group, and using in combination a compound (photoacidgenerator) capable of generating an acid upon irradiation with a farultraviolet ray has been developed. In the chemical amplification-typeresist, the acid generated in the exposed area causes a catalyticdecomposition reaction and thereby changes the solubility in adeveloper, so that a high-sensitivity and high-resolution pattern can beformed.

[0007] However, the compound having an aromatic group originally haslarge absorption in the region at a wavelength of 193 nm and therefore,when an ArF excimer laser ray (193 nm) is used, even the above-describedchemical amplification-type resist cannot provide sufficiently highperformance.

[0008] To solve this problem, the acid decomposable resin having a basicskeleton of poly(hydroxystyrene) is replaced by an acid decomposableresin having incorporated into the main or side chain of the polymer analicyclic structure having no absorption at 193 nm, with an attempt toimprove the chemical amplification-type resist.

[0009] However, this alicyclic resin has large absorption in the regionof 157 nm and therefore, with use of an F₂ excimer laser ray (157 nm),is still deficient in obtaining an objective pattern of 0.1 μm or less.On the other hand, Proc. SPIE., Vol. 3678, page 13 (1999) has reportedthat a resin having incorporated thereinto a fluorine atom(perfluoro-structure) has sufficiently high transparency to light at 157nm, and effective fluorine resin structures have been reported in Proc.SPIE., Vol. 3999, page 330 (2000), ibidem., page 357 (2000), ibidem.,page 365 (2000) and WO-00/17712.

[0010] The resists comprising such a fluorine resin are, however, notalways satisfied with respect to the dry etching resistance and sincethese resins show peculiar water repellency or oil repellencyattributable to the perfluoro-structure, improvement of the coatability(uniformity of the coated surface) and prevention of development defectsare being demanded.

SUMMARY OF THE INVENTION

[0011] Accordingly, an object of the present invention is to provide apositive resist composition suitable for the case using an exposurelight source of 160 nm or less, particularly a F₂ excimer laser ray (157nm). More specifically, the object of the present invention is toprovide a positive resist composition capable of exhibiting sufficientlyhigh transparency on use of a light source at 157 nm and satisfying theproperties with respect to the coatability and the development defect.

[0012] Another object of the present invention is to provide a positiveresist composition capable of forming a pattern with good sensitivityand high resolution and ensuring excellent dry etching resistance.

[0013] As a result of extensive investigations by taking account ofvarious properties described above, the present inventors have foundthat the objects of the present invention can be successfully attainedby the use of the following specific composition. The present inventionhas been accomplished based on this finding.

[0014] More specifically, the present invention has the followingconstructions.

[0015] (1) A positive resist composition comprising:

[0016] (A) a fluorine group-containing resin having: a structure whereinat least one of the main chain and the side chain of the polymerskeleton has at least one fluorine atom; and a group capable ofdecomposing under the action of an acid to increase the solubility in analkali developer;

[0017] (B) a compound capable of generating an acid upon irradiationwith at least one of an actinic ray or radiation; and

[0018] (C) a surfactant containing at least one of a silicon atom andfluorine atom.

[0019] (2) The positive resist composition as described in item (1),wherein the resin (A) comprises at least one of fluorinegroup-containing resins (i) and (ii) below:

[0020] (i) a fluorine group-containing resin having at least oneselected from a perfluoroalkylene group and a perfluoroarylene group asa part or all of the main chain of the polymer skeleton;

[0021] (ii) a fluorine group-containing resin having at least oneselected from a perfluoroalkyl group, a perfluoroaryl group, ahexafluoro-2-propanol group and a group wherein the OH group in ahexafluoro-2-propanol group is protected, as a part or all of the sidechain of the polymer skeleton.

[0022] (3) The positive resist composition as described in item (1) or(2), wherein the resin (A) contains at least one of repeating unitsrepresented by formulae (I) to (X):

[0023] wherein R₀ and R₁ each represents a hydrogen atom, a fluorineatom, or an alkyl, perfluoroalkyl, cycloalkyl or aryl group, each ofwhich may have a substituent;

[0024] R₂ to R₄ each represents an alkyl, perfluoroalkyl, cycloalkyl oraryl group, each of which may have a substituent and Ro and R₁ maycombine to form a ring, R₀ and R₂ may combine to form a ring and R₃ andR₄ may combine to form a ring;

[0025] R₅ represents a hydrogen atom, an alkyl, perfluoroalkyl,monocyclic or polycyclic cycloalkyl, acyl or alkoxycarbonyl group, eachof which may have a substituent;

[0026] R₆, R₇ and RB each represents a hydrogen atom, a halogen atom oran alkyl, perfluoroalkyl or alkoxy group, each of which may have asubstituent;

[0027] R₉ and R₁₀ each represents a hydrogen atom, a halogen atom, acyano group, or an alkyl or haloalkyl group, each of which may have asubstituent;

[0028] R₁₁, and R₁₂ each represents a hydrogen atom, a hydroxyl group, ahalogen atom a cyano group, an alkoxy group, an acyl group, an alkyl,cycloalkyl, alkenyl, aralkyl or aryl group, and the alkyl, thecycloalkyl, the alkenyl, the aralkyl or the aryl group each may have asubstituent;

[0029] R₁₃ and R₁₄ each represents a hydrogen atom, a halogen atom, acyano group, or an alkyl or haloalkyl, each of which may have asubstituent;

[0030] R₁₅ represents an alkyl, monocyclic or polycyclic cycloalkyl,alkenyl, aralkyl or aryl group, each of which has a fluorine atom;

[0031] R_(16,) R₁₇ and R₁₈ each represents a hydrogen atom, a halogenatom, a cyano group, or an alkyl, perfluoroalkyl, alkoxy or —CO—O—R₁₅group, each of which may have a substituent;

[0032] R₁₉, R₂₀ and R₂₁ each represents a hydrogen atom, a fluorine atomor an alkyl, monocyclic or polycyclic cycloalkyl, alkenyl, aralkyl, arylor alkoxy group, each of which has a fluorine atom, provided that atleast one of R₁₉, R₂₀ and R₂₁ is a group other than a hydrogen atom;

[0033] A₁ and A₂ each represents a single bond, a divalent alkylene,alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—, —CO—O—R₂₃— or—CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene, cycloalkylene orarylene group each may have a substituent;

[0034] R₂₂, R₂₃ and R₂₅ each represents a single bond or a divalentalkylene, alkenylene, cycloalkylene or arylene group, each of which mayhave an ether group, an ester group, an amide group, a urethane group ora ureido group;

[0035] R₂₄ represents a hydrogen atom or an alkyl, cycloalkyl, aralkylor aryl group, each of which may have a substituent;

[0036] n represents 0 or 1; and

[0037] x, y and z each represents an integer of 0 to 4.

[0038] (4) The positive resist composition as described in any one ofitem (1) to (3), wherein the resin (A) contains at least one ofrepeating units represented by formulae (XI) to (XIII):

[0039] wherein R₂₆, R₂₇ and R₃₂ each represents a hydrogen atom, ahalogen atom, a cyano group, or an alkyl or haloalkyl group, each ofwhich may have a substituent;

[0040] R₂₈ and R₃₃ each represents —C(R₃₆)(R₃₇)(R₃₈), —C(R₃₆)(R₃₇)(OR₃₉)or a group represented by formula (XIV):

[0041]  wherein R₂₉, R₃₀ and R₃₁ each represents a hydrogen atom, ahalogen atom, a cyano group or an alkyl, perfluoroalkyl, alkoxy or—CO—O—R₂₈ group, each of which may have a substituent;

[0042] R₃₄ and R₃₅ each represents a hydrogen atom, a hydroxyl group, ahalogen atom, a cyano group, an alkoxy group, an acyl group, an alkyl,cycloalkylene, alkenyl, aralkyl or aryl group, and the alkyl,cycloalkylene, alkenyl, aralkyl or aryl group each may have asubstituent;

[0043] R₃₆, R₃₇, R₃₈ and R₃₉ each represents an alkyl, cycloalkyl,alkenyl, aralkyl or aryl group, each of which may have a substituent,and two of R₃₆, R₃₇ and R₃₈, or two of R₃₆, R₃₇ and R₃₉ may combine toform a ring;

[0044] R₄₀ represents an alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl oraryl group, each of which may have a substituent;

[0045] A₃ and A₄ each represents a single bond, a divalent alkylene,alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—, —CO—O—R₂₃— or—CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene, cycloalkylene orarylene group, each of which may have a substituent;

[0046] R₂₂ to R₂₅ have the same meanings as above;

[0047] Z represents an atomic group constituting a monocyclic orpolycyclic alicyclic group together with the carbon atom; and

[0048] n represents 0 or 1.

[0049] (5) The positive composition as described in any one of items (1)to (4), wherein the resin (A) contains at least one of repeating unitsrepresented by formulae (XV) to (XVII):

[0050] wherein R₄₁ represents an alkyl, cycloalkyl, aralkyl or arylgroup, each of which may have a substituent;

[0051] R₄₂ represents a hydrogen atom, a halogen atom, a cyano group, oran alkyl or haloalkyl group, each of which may have a substituent;

[0052] A₅ represents a single bond, a divalent alkylene, alkenylene,cycloalkylene, arylene group, —O—CO—R₂₂—, —CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—,and the divalent alkylene, alkenylene, cycloalkylene or arylene groupeach may have a substituent;

[0053] R₂₂ to R₂₅ have the same meanings as above.

[0054] (6) The positive resist composition as described in any one ofitems (1) to (5), wherein the resin (A) contains: at least one ofrepeating units represented by formulae (I) to (III); and at least oneof repeating units represented by formulae (IV) to (VI):

[0055] wherein R₀ and R₁ each represents a hydrogen atom, a fluorineatom or an alkyl, perfluoroalkyl, cycloalkyl or aryl group, each ofwhich may have a substituent,

[0056] R₂ to R₄ each represents an alkyl, perfluoroalkyl, cycloalkyl oraryl group, each of which may have a substituent, and Ro and R₁ maycombine to form a ring, R₀ and R₂ may combine to form a ring, and R₃ andR₄ may combine to form a ring;

[0057] R₅ represents a hydrogen atom or an alkyl, perfluoroalkyl,monocyclic or polycyclic cycloalkyl, acyl or alkoxycarbonyl group, eachof which may have a substituent;

[0058] R₆, R₇ and R₈ each represents a hydrogen atom, a halogen atom oran alkyl, perfluoroalkyl or alkoxy group, each of which may have asubstituent;

[0059] R₉ represents a hydrogen atom, a halogen atom, a cyano group, oran alkyl or haloalkyl group, each of which may have a substituent;

[0060] A₁ and A₂ each represents a single bond, a divalent alkylene,alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—, —CO—O—R₂₃— or—CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene, cycloalkylene orarylene group each may have a substituent;

[0061] R₂₂, R₂₃ and R₂₅ each represents a single bond or a divalentalkylene, alkenylene, cycloalkylene or arylene group, each of which mayhave an ether group, an ester group, an amide group, a urethane or aureido group;

[0062] R₂₄ represents a hydrogen atom or an alkyl, cycloalkyl, aralkylor aryl group, each of which may have a substituent; and

[0063] n represents 0 or 1.

[0064] (7) The positive resist composition as described in any one ofitems (1) to (5), wherein the resin (A) contains: at least one ofrepeating units represented by formulae (IV) to (VI) below; and at leastone of repeating units represented by formulae (VIII) to (X) below:

[0065] wherein R₅ represents a hydrogen atom or an alkyl,perfluoroalkyl, monocyclic or polycyclic cycloalkyl, acyl oralkoxycarbonyl group, each of which may have a substituent;

[0066] R₆, R₇ and R₈ each represents a hydrogen atom, a halogen atom oran alkyl, perfluoroalkyl or alkoxy group, each of which may have asubstituent;

[0067] R₉ represents a hydrogen atom, a halogen atom, a cyano group, oran alkyl or haloalkyl group, each of which may have a substituent;

[0068] R₁₃ and R₁₄ each represents a hydrogen atom, a halogen atom, acyano group, or an alkyl or haloalkyl group, each of which may have asubstituent;

[0069] R₁₅ represents an alkyl, monocyclic or polycyclic cycloalkyl,alkenyl, aralkyl or aryl group, each of which has a fluorine atom;

[0070] R₁₆, R₁₇ and R₁₈ each represents a hydrogen atom, a halogen atom,a cyano group, or an alkyl, perfluoroalkyl, alkoxy or —CO—O—R₁₅ group,each of which may have a substituent;

[0071] R₁₉, R₂₀ and R₂₁ each represents a hydrogen atom, a fluorine atomor an alkyl, monocyclic or polycyclic cycloalkyl, alkenyl, aralkyl, arylor alkoxy group, each of which has a fluorine atom, provided that atleast one of R₁₉, R₂₀ and R₂₁ is a group other than a hydrogen atom;

[0072] A₁ and A₂ each represents a single bond, a divalent alkylene,alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—, —CO—O—R₂₃— or—CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene, cycloalkylene orarylene group each may have a substituent;

[0073] R₂₂, R₂₃ and R₂₅ each represents a single bond or a divalentalkylene, alkenylene, cycloalkylene or arylene group, each of which mayhave an ether group, an ester group, an amide group, a urethane group ora ureido group;

[0074] R₂₄ represents a hydrogen atom or an alkyl, cycloalkyl, aralkylor aryl group, each of which may have a substituent;

[0075] n represents 0 or 1; and

[0076] x, y and z each represents an integer of 0 to 4.

[0077] (8) The positive resist composition as described in any one ofitems (1) to (5), wherein the resin (A) contains: at least one ofrepeating units represented by formulae (IV) to (VII) below; and atleast one of repeating units represented by formulae (XV) to (XVII)below:

[0078] wherein R₅ represents a hydrogen atom or an alkyl,perfluoroalkyl, monocyclic or polycyclic cycloalkyl, acyl oralkoxycarbonyl group, each of which may have a substituent;

[0079] R₆, R₇ and R₈ each represents a hydrogen atom, a halogen atom, oran alkyl, perfluoroalkyl or alkoxy group, each of which may have asubstituent;

[0080] R₉ and R₁₀ each represents a hydrogen atom, a halogen atom, acyano group, or an alkyl or haloalkyl group, each of which may have asubstituent;

[0081] R₁₁ and R₁₂ each represents a hydrogen atom, a hydroxyl group, ahalogen atom, a cyano group, an alkoxy group, an acyl group, an alkyl,cycloalkyl, alkenyl, aralkyl or aryl group, and the alkyl, cycloalkyl,alkenyl, aralkyl or aryl group each may have a substituent;

[0082] A₁ and A₂ each represents a single bond or a divalent alkylene,alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—, —CO—O—R₂₃— or—CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene, cycloalkylene orarylene group each may have a substituent;

[0083] R₂₂, R₂₃ and R₂₅ each represents a single bond or a divalentalkylene, alkenylene, cycloalkylene or arylene group, each of which mayhave an ether group, an ester group, an amide group, a urethane group ora ureido group;

[0084] R₂₄ represents a hydrogen atom or an alkyl, cycloalkyl, aralkylor aryl group, each of which may have a substituent;

[0085] n represents 0 or 1;

[0086] R₄₁ represents an alkyl, cycloalkyl, aralkyl or aryl group, eachof which may have a substituent;

[0087] R₄₂ represents a hydrogen atom, a halogen atom, a cyano group, oran alkyl or haloalkyl group, each of which may have a substituent; and

[0088] A₅ represents a single bond, a divalent alkylene, alkenylene,cycloalkylene, arylene group, —O—CO—R₂₂—, —CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—,and the divalent alkylene, alkenylene, cycloalkylene or arylene groupeach may have a substituent.

[0089] (9) The positive resist composition as described in item (1) or(2), wherein the resin (A) contains: at least one of repeating unitsrepresented by formula (IA) below; and at least one of repeating unitsrepresented by formula (IIA) below:

[0090] wherein R_(1a) and R_(5a) each represents a hydrogen atom, ahalogen atom, a cyano group or an alkyl group which may have asubstituent;

[0091] R_(2a), R_(3a), R_(6a) and R_(7a) each represents a hydrogenatom, a halogen atom, a cyano group, a hydroxyl group or an alkyl,cycloalkyl, alkoxy, acyl, acyloxy, alkenyl, aryl or aralkyl group, eachof which may have a substituent;

[0092] R_(50a) to R_(55a) each represents a hydrogen atom, a fluorineatom or an alkyl group which may have a substituent, and at least one ofR_(50a) to R_(55a) represents a fluorine atom or an alkyl group where atleast one hydrogen atom is substituted by a fluorine atom;

[0093] R_(56a) represents a hydrogen atom or an alkyl, cycloalkyl, acylor alkoxycarbonyl group, each of which may have a substituent;

[0094] R_(4a) represents a group represented by formula (IVA) or (VA):

[0095]  wherein in formula (IVA), R_(11a), R_(12a) and R_(13a) eachrepresents an alkyl, cycloalkyl, alkenyl, aralkyl or aryl group, each ofwhich may have a substituent; and

[0096] in formula (VA), R_(14a) and R_(15a) each represents a hydrogenatom or an alkyl group which may have a substituent; and

[0097] R_(16a) represents an alkyl, cycloalkyl, aralkyl or aryl group,each of which may have a substituent, and two of R_(14a) to R_(16a) maycombine to form a ring.

[0098] (10) The positive resist composition as described in item (1) or(2), wherein the resin (A) contains: at least one of repeating unitsrepresented by formula (IIA) below; and at least one of repeating unitsrepresented by (VIA) below:

[0099] wherein in formula (IIA), R_(5a) represents a hydrogen atom, ahalogen atom, a cyano group or an alkyl group which may have asubstituent;

[0100] R_(6a) and R_(7a) each represents a hydrogen atom, a halogenatom, a cyano group, a hydroxyl, or an alkyl, cycloalkyl, alkoxy, acyl,acyloxy, alkenyl, aryl or aralkyl group, each of which may have asubstituent;

[0101] R_(50a) to R_(55a) each represents a hydrogen atom, a fluorineatom or an alkyl group which may have a substituent, and at least one ofR_(50a) to R_(55a) represents a fluorine atom or an alkyl group where atleast one hydrogen atom is substituted by a fluorine atom;

[0102] R_(56a) represents a hydrogen atom or an alkyl, cycloalkyl, acylor alkoxycarbonyl group, each of which may have a substituent;

[0103] in formula (VIA), R_(17a1) and R_(17a2) each represents ahydrogen atom, a halogen atom, a cyano group or an alkyl group which mayhave a substituent;

[0104] R_(18a) represents —C(R_(18a1))(R_(18a2))(R_(18a3)) or—C(R_(18a1))(R_(18a2))(OR_(18a4))

[0105] R_(18a1) to R_(18a4) each represents a hydrogen atom or an alkyl,cycloalkyl, alkenyl, aralkyl or aryl group, each of which may have asubstituent, and two of R_(18a1), R_(18a2) and R_(18a3) or two ofR_(18a1), R_(18a2) and R_(18a4) may combine to form a ring; and

[0106] A₀ represents a single bond or a divalent linking group which mayhave a substituent.

[0107] (11) The positive resist composition as described in item (10),wherein in formula (VIA), R_(18a) is a group represented by formula(VIA-A):

[0108] wherein R_(18a5) and R_(18a6) each represents an alkyl groupwhich may have a substituent; and R_(18a7) represents a cycloalkyl groupwhich may have a substituent.

[0109] (12) The positive resist composition as described in item (10),wherein in formula (VIA), R_(18a) is a group represented by formula(VIA-B):

[0110] wherein R_(18a8) represents an alkyl, alkenyl, alkynyl, aralkylor aryl group, each of which may have a substituent.

[0111] (13) The positive resist composition as described in item (9),wherein at least one of R_(1a) in formula (IA) and R_(5a) in formula(IIA) is a trifluoromethyl group.

[0112] (14) The positive resist composition as described in item (10),wherein at least one of R_(5a) in formula (IIA) and R_(17a2) in formula(VIA) is a trifluoromethyl group.

[0113] (15) The positive resist composition as described in item (9) or(10), wherein the resin (A) further contains at least one of repeatingunits represented by formulae (IIIA) and (VIIA):

[0114] wherein in formula (IIIA), R_(8a) represents a hydrogen atom, ahalogen atom, a cyano group or an alkyl group which may have asubstituent; R_(9a) and R_(10a) each represents a hydrogen atom, ahalogen atom, a cyano group or an alkyl, cycloalkyl, alkoxy, acyl,acyloxy, alkenyl, aryl or aralkyl group, each of which may have asubstituent; and

[0115] in formula (VIIA), R_(19a) and R_(20a) each represents a hydrogenatom, a halogen atom, a cyano group or an alkyl group which may have asubstituent, R_(21a) represents a hydrogen atom, a halogen atom, analkyl which may have a substituent or —A₁—CN group; and A₁ represents asingle bond or a divalent linking group.

[0116] (16) The positive resist composition as described in any one ofitems (1) to (15), which further comprises a compound containing a basicnitrogen atom.

[0117] (17) The positive resist composition as described in any one ofitems (1) to (16), wherein the compound (B) comprises at least onecompound selected from sulfonium salt and iodonium salt compoundscapable of generating at least one of acids (i) to (iii) below uponirradiation with one of an actinic ray and radiation:

[0118] (i) a perfluoroalkylsulfonic acid having 2 or more carbon atoms;

[0119] (ii) a perfluoroarylsulfonic acid; and

[0120] (iii) an arylsulfonic acid having a perfluoroalkyl group as asubstituent.

[0121] (18) The positive resist composition as described in any one ofitems (1) to 17), which is a composition to be irradiated with anultraviolet ray having a wave length of 160 nm or less.

[0122] (19) The positive resist composition as described in item (18),wherein the ultraviolet ray is F₂ excimer laser ray having a wave lengthof 157 nm.

DETAILED DESCRIPTION OF THE INVENTION

[0123] The compounds for use in the present invention are described indetail below.

[0124] [1] Fluorine Group-Containing Resin (A) of the Present Invention

[0125] The fluorine group-containing resin (A) for use in the presentinvention is a resin characterized by having on the main chain and/orthe side chain of the polymer a structure such that the fluorine atom issubstituted, and having a group capable of decomposing under the actionof an acid to increase the solubility in an alkali developer. This ispreferably a fluorine group-containing resin having on the main chain ofthe polymer skeleton at least one site selected from a perfluoroalkylenegroup and a perfluoro-arylene group, or a fluorine group-containingresin having on the side chain of the polymer skeleton at least one siteselected from a perfluoroalkyl group, a perfluoroaryl group, ahexafluoro-2-propanol group and a group resulting from protecting the OHgroup of a hexafluoro-2-propanol group.

[0126] To speak specifically, this is a resin having at least onerepeating unit represented by formulae (I) to (X), more preferably afluorine group-containing resin containing an acid-decomposable grouphaving at least one repeating unit represented by formulae (XI) to(XIII).

[0127] Also, for controlling the physical properties of the fluorinegroup-containing resin, such as hydro-philicity/hydrophobicity, glasstransition point and transmittance to exposure light or for controllingthe polymerizability on the synthesis of polymer, the resin may have atleast one repeating unit derived from a vinyl compound containing amaleic anhydride, a vinyl ether or a cyano group, each of which isrepresented by formula (XV), (XVI) or (XVII).

[0128] In formulae, R₀ and R₁ each represents a hydrogen atom, afluorine atom or an alkyl, perfluoroalkyl, cycloalkyl or aryl groupwhich may have a substituent.

[0129] R₂ to R₄ each represents an alkyl, perfluoroalkyl, cycloalkyl oraryl group which may have a substituent. Also, each of the pairs R₀ andR₁, R₀ and R₂, and R₃ and R₄ may combine to form a ring.

[0130] R₅ represents a hydrogen atom or an alkyl, perfluoroalkyl, amonocyclic or polycyclic cycloalkyl, acyl or alkoxycarbonyl group whichmay have a substituent.

[0131] R₆, R₇ and R₈, which may be identical or different, eachrepresents a hydrogen atom, a halogen atom or an alkyl, perfluoroalkylor alkoxy group which may have a substituent.

[0132] R₉and R₁₀, which may be identical or different, each represents ahydrogen atom, a halogen atom, a cyano group or an alkyl or haloalkylgroup which may have a substituent.

[0133] R₁₁ and R₁₂, which may be identical or different, each representsa hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, analkoxy group, an acyl group or an alkyl, cycloalkyl, alkenyl, aralkyl oraryl group which may have a substituent.

[0134] R₁₃ and R₁₄, which may be identical or different, each representsa hydrogen atom, a halogen atom, a cyano group or an alkyl or haloalkylgroup which may have a substituent.

[0135] R₁₅ represents an alkyl, monocyclic or polycyclic cycloalkyl,alkenyl, aralkyl or aryl group having a fluorine atom.

[0136] R₁₆, R₁₇ and R₁₈, which may be identical or different, eachrepresents a hydrogen atom, a halogen atom, a cyano group, a cyano groupor an alkyl, perfluoroalkyl, alkoxy or —CO—O—R₁₅ group which may have asubstituent.

[0137] R₁₉, R₂₀ and R₂₁, which may be identical or different, eachrepresents a hydrogen atom, a fluorine atom or an alkyl, monocyclic orpolycyclic cycloalkyl, alkenyl, aralkyl, aryl or alkoxy group having afluorine atom. However, at least one of R₁₉, R₂₀ and R₂₁ is a groupother than a hydrogen atom.

[0138] A₁ and A₂ each represents a single bond, a divalent alkylene,alkenylene, cycloalkylene or arylene group which may have a substituent,—O—CO—R₂₂—, —CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—.

[0139] R₂₂, R₂₃ and R₂₅, which may be identical or different, eachrepresents a single bond or a divalent alkylene, alkenylene,cycloalkylene or arylene group which may have an ether group, an estergroup, an amide group, a urethane group or a ureido group. R₂₄represents a hydrogen atom or an alkyl, cycloalkyl, aralkyl or arylgroup which may have a substituent.

[0140] R₂₆, R₂₇ and R₃₂, which may be identical or different, eachrepresents a hydrogen atom, a halogen atom, a cyano group or an alkyl orhaloalkyl group which may have a substituent.

[0141] R₂₈ and R₃₃ each represents —C(R₃₆E)(R₃₇)(R₃₈),—C(R₃₆)(R₃₇)(OR₃₉) or a group represented by formula (XIV).

[0142] R₂₉, R₃₀ and R₃₁, which may be identical or different, eachrepresents a hydrogen atom, a halogen atom, a cyano group or an alkyl,perfluoroalkyl, alkoxy or —CO—O—R₂₈ group which may have a substituent.

[0143] R₃₄ and R₃₅, which may be identical or different, each representsa hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, analkoxy group, an acyl group or an alkyl, cycloalkyl, alkenyl, aralkyl oraryl group which may have a substituent.

[0144] R₃₆, R₃₇, R₃₈ and R₃₉, which may be identical or different, eachrepresents an alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl or aryl groupwhich may have a substituent. Two of R₃₆, R₃₇ and R₃₈ or two of R₃₆, R₃₇and R₃₉ may combine to form a ring. The formed ring may contain an oxogroup.

[0145] R₄₀ represents an alkyl, cycloalkyl, alkenyl, aralkyl or arylgroup which may have a substituent.

[0146] A₃ and A₄ each represents a single bond, a divalent alkylene,alkenylene, cycloalkylene or arylene group which may have a substituent,—O—CO—R₂₂—, —CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—.

[0147] Z represents an atomic group constituting a monocyclic orpolycyclic alicyclic group together with the carbon atom.

[0148] R₄₁ represents an alkyl, cycloalkyl, aralkyl or aryl group whichmay have a substituent.

[0149] R₄₂ represents a hydrogen atom, a halogen atom, a cyano group oran alkyl or haloalkyl group which may have a substituent.

[0150] A₅ represents a single bond, a divalent alkylene, alkenylene,cycloalkylene or arylene group which may have a substituent, —O—CO—R₂₂—,—CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—.

[0151] n represents 0 or 1, and x, y and z represents an integer of 0 to4.

[0152] More preferred examples of the fluorine group-containing resin(A) for use in the present invention include a resin containing at leastone repeating unit represented by formula (IA) and at least onerepeating unit represented by formula (IIA), and a resin containing atleast one repeating unit represented by formula (IIA) and at least onerepeating unit represented by formula (VIA) These fluorinegroup—containing resins (A) each may further contain at least onerepeating unit represented by formula (IIA) or (VIIA). In these fluorinegroup-containing resins (A), R_(18a) of formula (VIA) is preferablyrepresented by formula (VIA-A) or (VIA-B). Furthermore, in thesefluorine group-containing resins (A), at least one of R_(1a) of formula(IA) and R_(5a) of formula (IIA) is preferably a trifluoromethyl group,and at least one of Rsa of formula (IIA) and R_(17a2) of formula (VIA)is preferably a trifluoromethyl group.

[0153] The fluorine group-containing resin (A) containing at least onerepeating unit represented by formula (IA) and at least one repeatingunit represented by formula (IIA), and the fluorine group-containingresin (A) containing at least one repeating unit represented by formula(IIA) and at least one repeating unit represented by formula (VIA) eachmay further contain a repeating unit represented by formulae (I) to (V).

[0154] In formulae (IA) and (IIA), R_(1a) and R_(5a) may be identical ordifferent and each represents a hydrogen atom, a halogen atom, a cyanogroup or an alkyl group which may have a substituent. R_(2a) , R_(3a) ,R_(6a) and R_(7a) may be identical or different and each represents ahydrogen atom, a halogen atom, a cyano group, a hydroxyl group or analkyl, cycloalkyl, alkoxy, acyl, acyloxy, alkenyl, aryl or aralkyl groupwhich may have a substituent. R_(50a) to R_(55a) may be identical ordifferent and each represents a hydrogen atom, a fluorine atom or analkyl group which may have a substituent. However, at least one ofR_(50a) to R_(55a) represents a fluorine atom or an alkyl group where atleast one hydrogen atom is substituted by a fluorine atom. R_(56a)represents a hydrogen atom or an alkyl, cycloalkyl, acyl oralkoxycarbonyl group which may have a substituent, preferably a hydrogenatom. R_(4a) represents a group represented by formula (IVA) or (VA).

[0155] In formula (IVA), R_(11a), R_(12a) and R_(13a) may be identicalor different and each represents an alkyl, cycloalkyl, alkenyl, aralkylor aryl group which may have a substituent.

[0156] In formula (VA), R_(14a) and R_(15a) may be identical ordifferent and each represents a hydrogen atom or an alkyl group whichmay have a substituent. R_(16a) represents an alkyl, cycloalkyl, aralkylor aryl group which may have a substituent. Two of R_(14a) to R_(16a)may combine to form a ring.

[0157] In formula (VIA), R_(17a1) and R_(17a2) may be identical ordifferent and each represents a hydrogen atom, a halogen atom, a cyanogroup or an alkyl group which may have a substituent. R_(18a) represents—C(R_(18a1))(R_(18a2))(R_(18a3)) or —C(R_(18a1))(R_(18a2))(OR_(18a4)).R_(18a1) to R_(18a4) may be identical or different and each represents ahydrogen atom or an alkyl, cycloalkyl, alkenyl, aralkyl or aryl groupwhich may have a substituent. Two of R_(18a1), R_(18a2) and R_(18a3) ortwo of R_(18a1) , R_(18a2) and R_(18a4) may combine to form a ring. A₀represents a single bond or a divalent linking group which may have asubstituent, preferably a single bond.

[0158] In formula (VIA-A), R_(18a5) and R_(18a6) may be identical ordifferent and each represents an alkyl group which may have asubstituent. R_(18a7) represents a cycloalkyl group which may have asubstituent.

[0159] In formula (VIA-B), R_(18a8) represents an alkyl, alkenyl,alkynyl, aralkyl or aryl group which may have a substituent.

[0160] In formula (IIIA), R_(8a) represents a hydrogen atom, a halogenatom, a cyano group or an alkyl group which may have a substituent.R_(9a) and R_(10a) may be identical or different and each represents ahydrogen atom, a halogen atom, a cyano group or an alkyl, cycloalkyl,alkoxy, acyl, acyloxy, alkenyl, aryl or aralkyl group which may have asubstituent.

[0161] In formula (VIIA), R_(19a) and R_(20a) may be identical ordifferent and each represents a hydrogen atom, a halogen atom, a cyanogroup or an alkyl group which may have a substituent. R_(21a) representsa hydrogen atom, a halogen atom, an alkyl group which may have asubstituent or an —A₁—CN group. A₁ represents a single bond or adivalent linking group.

[0162] The alkyl group is, for example, an alkyl group having from 1 to8 carbon atoms and specific preferred examples thereof include a methylgroup, an ethyl group, a propyl group, an n-butyl group, a sec-butylgroup, a hexyl group, a 2-ethylhexyl group and an octyl group.

[0163] The cycloalkyl group may be monocyclic or polycyclic. Themonocyclic cycloalkyl group is a cycloalkyl group having from 3 to 8carbon atoms and preferred examples thereof include a cyclopropyl group,a cyclopentyl group, a cyclohexyl group, a cycloheptyl group and acyclooctyl group. The polycyclic cycloalkyl group is a cycloalkyl grouphaving from 6 to 20 carbon atoms and preferred examples thereof includean adamantyl group, a norbornyl group, an isoboronyl group, a camphanylgroup, a dicyclopentyl group, an a-pinel group, a tricyclodecanyl group,a tetracyclododecyl group and an androstanyl group. However, in themonocyclic or polycyclic alkyl group, the carbon atom may be substitutedby a hetero atom such as oxygen atom.

[0164] The perfluoroalkyl group is, for example, a perfluoroalkyl grouphaving from 4 to 12 carbon atoms and specific preferred examples thereofinclude a perfluorobutyl group, a perfluorohexyl group, a perfluorooctylgroup, a perfluorooctylethyl group and a perfluorododecyl group.

[0165] The haloalkyl group is, for example, a haloalkyl group havingfrom 1 to 4 carbon atoms and specific preferred examples thereof includea chloromethyl group, a chloroethyl group, a chloropropyl group, achlorobutyl group, a boromomethyl group and a bromoethyl group.

[0166] The aryl group is, for example, an aryl group having from 6 to 15carbon atoms and specific preferred examples thereof include a phenylgroup, a tolyl group, a dimethylphenyl group, a 2,4,6-trimethylphenylgroup, a naphthyl group, an anthryl group and a 9,10-dimethoxyanthrylgroup.

[0167] The aralkyl group is, for example, an aralkyl group having from 7to 12 carbon atoms and specific preferred examples thereof include abenzyl group, a phenethyl group and a naphthylmethyl group.

[0168] The alkenyl group is, for example, an alkenyl group having from 2to 8 carbon atoms and specific preferred examples thereof include avinyl group, an allyl group, a butenyl group and a cyclohexenyl group.

[0169] The alkoxy group is, for example, an alkoxy group having from 1to 8 carbon atoms and specific preferred examples thereof include amethoxy group, an ethoxy group, an n-propoxy group, an iso-propoxygroup, a butoxy group, a pentoxy group, an allyloxy group and an octoxygroup.

[0170] The acyl group is, for example, an acyl group having from 1 to 10carbon atoms and specific preferred examples thereof include a formylgroup, an acetyl group, a propanoyl group, a butanoyl group, a pivaloylgroup, an octanoyl group and a benzoyl group.

[0171] The acyloxy group is preferably an acyloxy group having from 2 to12 carbon atoms and examples thereof include an acetoxy group, apropionyloxy group and a benzoyloxy group.

[0172] The alkynyl group is preferably an alkynyl group having from 2 to5 carbon atoms and examples thereof include an ethynyl group, a propynylgroup and a butynyl group.

[0173] Examples of the alkoxycarbonyl group include an i-propoxycarbonylgroup, a tert-butoxycarbonyl group, a tert-amyloxycarbonyl group and a1-methyl-1-cyclohexyloxy-carbonyl group. The alkoxycarbonyl group ispreferably a secondary alkoxycarbonyl group, more preferably a tertiaryalkoxycarbonyl group.

[0174] Examples of the halogen atom include a fluorine atom, a chlorineatom, a bromine atom and an iodine atom.

[0175] The alkylene group is preferably an alkylene group having from 1to 8 carbon atoms, such as methylene group, ethylene group, propylenegroup, butylene group, hexylene group and octylene group, which may havea substituent.

[0176] The alkenylene group is preferably an alkenylene group havingfrom 2 to 6 carbon atoms, such as ethenylene group, propenylene groupand butenylene group, which may have a substituent.

[0177] The cycloalkylene group is preferably a cycloalkylene grouphaving from 5 to 8 carbon atoms, such as cyclopentylene group andcyclohexylene group, which may have a substituent.

[0178] The arylene group is preferably an arylene group having from 6 to15 carbon atoms, such as phenylene group, tolylene group and naphthylenegroup, which may have a substituent.

[0179] The divalent linking group is a divalent alkylene, cycloalkylene,alkenylene or arylene group which may have a substituent, —O—CO—R_(22a),—CO—O—R_(23a)— or —CO—N(R_(24a))—R_(25a)—(wherein R_(22a), R_(23a) andR_(25a), which may be identical or different, each represents a singlebond or a divalent alkylene, alkenylene, cycloalkylene or arylene groupwhich may have an ether group, an ester group, an amido group, aurethane group or a ureido group, and R_(24a) represents a hydrogen atomor an alkyl, cycloalkyl, aralkyl or aryl group which may have asubstituent).

[0180] The ring formed resulting from R₀ and R₁, R₀ and R₂, or R₃ and R₄combining with each other is, for example, a 5-, 6- or 7-membered ringand specific examples thereof include a pentane ring, a hexane ring, afuran ring, a dioxonol ring and a 1,3-dioxolan ring, which are eachsubstituted by fluorine.

[0181] The ring formed resulting from two of R₃₆ to R₃₈ or two of R₃₆ toR₃₇ and R₃₉ combining with each other is, for example, a 3-, 4-, 5-, 6-,7- or 8-membered ring and specific preferred examples thereof include acyclopropane ring, a cyclopentane ring, a cyclohexane ring, a furan ringand a pyran ring.

[0182] The ring formed resulting from two of R_(14a) to R_(16a), two ofR_(18a1) to R_(18a3), or two of R_(18a1), R_(18a2) and R_(18a4)combining with each other is preferably a 3-, 4-, 5-, 6-, 7- or8-membered ring and examples thereof include a cyclopropane ring, acyclopentane ring, a cyclohexane ring, a tetramethylene oxide ring, apentamethylene oxide ring, a hexamethylene oxide ring, a furan ring, apyran ring, a dioxonol ring and a 1,3-dioxolan ring.

[0183] Z represents an atomic group constituting a monocyclic orpolycyclic alicyclic group. In the case of a monocyclic group, theformed alicyclic group is an alicyclic group having from 3 to 8 carbonatoms and preferred examples thereof include a cyclopropyl group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group and acyclooctyl group. In the case of a polycyclic group, the formedalicyclic group is an alicyclic group having from 6 to 20 carbon atomsand preferred examples thereof include an adamantyl group, a norbornylgroup, an isoboronyl group, a camphanyl group, a dicyclopentyl group, ana-pinel group, a tricyclodecanyl group, a tetracyclododecyl group and anandrostanyl group.

[0184] Examples of the substituent substituted to these groups includesubstituents having active hydrogen, such as alkyl group, cycloalkylgroup, aryl group, amino group, amido group, ureido group, urethanegroup, hydroxyl group and carboxyl group, a halogen atom (e.g.,fluorine, chlorine, bromine, iodine), an alkoxy group (e.g., methoxy,ethoxy, propoxy, butoxy), a thioether group, an acyl group (e.g.,acetyl, propanoyl, benzoyl), an acyloxy group (e.g., acetoxy,propanoyloxy, benzoyloxy), an alkoxycarbonyl group (e.g.,methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl), a cyano group and anitro group.

[0185] Examples of the alkyl group, the cycloalkyl group and the arylgroup include those described above, but the alkyl group may further besubstituted by a fluorine atom or a cycloalkyl group.

[0186] Examples of the group capable of decomposing under the action ofan acid to show alkali solubility, contained in the fluorinegroup-containing resin for use in the present invention, include—O—C(R₃₆)(R₃₇)(R₃₈), —O—C(R₃₆)(R₃₇)(OR₃₉), —O—COO—C(R₃₆)(R₃₇)(R₃₈),—O—C(R₀₁)(R₀₂)COO—C(R₃₆)(R₃₇)(R₃₈), —COO—C(R₃₆)(R₃₇)(R₃₈) and—COO—C(R₃₆)(R₃₇)(OR₃₉) (wherein R₃₆ to R₃₉ have the same meanings asabove, and R₀₁ and R₀₂ each represents a hydrogen atom or theabove-described alkyl, cycloalkyl, alkenyl, aralkyl or aryl group whichmay have a substituent.

[0187] Specific preferred examples thereof include an ether or estergroup of a tertiary alkyl group such as tert-butyl group, tert-amylgroup, 1-alkyl-1-cyclohexyl group, 2-alkyl-2-adamantyl group,2-adamantyl-2-propyl group and 2-(4-methylcyclohexyl)-2-propyl group, anacetal or acetal ester group such as 1-alkoxy-1-ethoxy group andtetrahydropyranyl group, a tert-alkylcarbonate group and atert-alkylcarbonylmethoxy group.

[0188] The total content of the repeating units represented by formulae(I) to (X) is generally from 10 to 80 mol %, preferably from 30 to 70mol %, more preferably from 35 to 65 mol %, in the entire polymercomposition.

[0189] The content of the repeating unit represented by formulae (XI) to(XIII) is generally from 0 to 70 mol %, preferably from 10 to 60 mol %,more preferably from 20 to 50 mol %, in the entire polymer composition.

[0190] The content of the repeating unit represented by formulae (XV) to(XVII) is generally from 0 to 70 mol %, preferably from 10 to 60 mol %,more preferably from 20 to 50 mol %.

[0191] The resin (A) for use in the present invention more preferablyhas at least one repeating unit represented by formulae (I) to (III) andat least one repeating unit represented by formulae (IV) to (VI).

[0192] Similarly to the above, the resin (A) for use in the presentinvention more preferably has at least one repeating unit represented byformulae (IV) to (VI) and at least one repeating unit represented byformulae (VIII) to (X).

[0193] Furthermore, similarly to the above, the resin (A) for use in thepresent invention more preferably has at least one repeating unitrepresented by formulae (IV) to (VII) and at least one repeating unitrepresented by formulae (XV) to (XVII).

[0194] By containing the repeating units as such, the resin can besufficiently elevated in the transmittance at 157 nm and suppressed inthe reduction of the dry etching resistance.

[0195] In the case where the resin (A) for use in the present inventionhas at least one repeating unit represented by formulae (I) to (III) andat least one repeating unit represented by formulae (IV) to (VI), thetotal content of the repeating units represented by formulae (I) to(III) used in the entire polymer composition is generally from 0 to 70mol %, preferably from 10 to 60 mol %, more preferably from 20 to 50 mol%.

[0196] The total content of the repeating units represented by formulae(IV) to (VI) used in the entire polymer composition is generally from 10to 80 mol %, preferably from 30 to 70 mol %, more preferably from 35 to65 mol %.

[0197] In the case where the resin (A) for use in the present inventionhas at least one repeating unit represented by formulae (IV) to (VI) andat least one repeating unit represented by formulae (VIII) to (X), thetotal content of the repeating units represented by formulae (IV) to(VI) used in the entire polymer composition is generally from 10 to 80mol %, preferably from 30 to 70 mol %, more preferably from 35 to 65 mol%.

[0198] The total content of the repeating units represented by formulae(VIII) to (X) used in the entire polymer composition is generally from 0to 70 mol %, preferably from 10 to 60 mol %, more preferably from 20 to50 mol %.

[0199] In the case where the resin (A) for use in the present inventionhas at least one repeating unit represented by formulae (IV) to (VII)and at least one repeating unit represented by formulae (XV) to (XVII),the total content of the repeating units represented by formulae (IV) to(VII) used in the entire polymer composition is generally from 10 to 80mol %, preferably from 30 to 70 mol %, more preferably from 35 to 65 mol%.

[0200] The total content of the repeating units represented by formulae(XV) to (XVII) used in the entire polymer composition is generally from0 to 70 mol %, preferably from 10 to 60 mol %, more preferably from 20to 50 mol %.

[0201] In the fluorine-containing resin (A) having at least onerepeating unit represented by formula (IA) and at least one repeatingunit represented by formula (IIA), the content of the repeating unitrepresented by formula (IA) is generally from 5 to 80 mol %, preferablyfrom 10 to 75 mol %, more preferably from 20 to 70 mol %.

[0202] In the fluorine-containing resin (A) having at least onerepeating unit represented by formula (IA) and at least one repeatingunit represented by formula (IIA), the content of the repeating unitrepresented by formula (IIA) is generally from 5 to 80 mol %, preferablyfrom 10 to 70 mol %, more preferably from 20 to 65 mol %.

[0203] In the fluorine-containing resin (A) having at least onerepeating unit represented by formula (IA) and at least one repeatingunit represented by formula (VIA), the content of the repeating unitrepresented by formula (IIA) is generally from 5 to 80 mol %, preferablyfrom 10 to 70 mol %, more preferably from 20 to 65 mol %.

[0204] In the fluorine-containing resin (A) having at least onerepeating unit represented by formula (IIA) and at least one repeatingunit represented by formula (VIA), the content of the repeating unitrepresented by formula (VIA) is generally from 5 to 80 mol %, preferablyfrom 10 to 70 mol %, more preferably from 20 to 65 mol %.

[0205] In these fluorine-containing resin (A), the content of therepeating unit represented by formula (IIIA) is generally from 1 to 40mol %, preferably from 3 to 35 mol %, more preferably from 5 to 30 mol%.

[0206] In these fluorine-containing resin (A), the content of therepeating unit represented by formula (VIIA) is generally from 1 to 40mol %, preferably from 3 to 35 mol %, more preferably from 5 to 30 mol%.

[0207] In the resin (A) for use in the present invention, in addition tothe above-described repeating structural units, another polymerizablemonomer may also be copolymerized so as to improve the performance ofthe positive resist of the present invention.

[0208] Examples of the copolymerizable monomer which can be used includecompounds having one addition-polymerizable unsaturated bond, selectedfrom acrylic acid esters other than those described above, acrylamides,methacrylic acid esters, methacrylamides, allyl compounds, vinyl ethers,vinyl esters, styrenes and crotonic acid esters.

[0209] Specific examples thereof include acrylic acid esters such asalkyl (the alkyl group is preferably an alkyl group having from 1 to 10carbon atoms) acrylate (e.g., methyl acrylate, ethyl acrylate, propylacrylate, tert-butyl acrylate, amyl acrylate, cyclohexyl acrylate,ethylhexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethylacrylate, 2-hydroxyethyl acrylate, 2,2-dimethylhydroxypropyl acrylate,5-hydroxypentyl acrylate, trimethylolpropane monoacrylate,pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate,furfuryl acrylate, tetrahydrofurfuryl acrylate) and aryl acrylate (e.g.,phenyl acrylate);

[0210] methacrylic acid esters such as alkyl (the alkyl group ispreferably an alkyl group having from 1 to 10 carbon atoms) methacrylate(e.g., methyl methacrylate, ethyl methacrylate, propyl methacrylate,isopropyl methacrylate, tert-butyl methacrylate, amyl methacrylate,hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate,chlorobenzyl methacrylate, octyl methacrylate, 2-hydroxyethylmethacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate,2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropanemonomethacrylate, pentaerythritol monomethacrylate, glycidylmethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate)and aryl methacrylate (e.g., phenyl methacrylate, cresyl methacrylate,naphthyl methacrylate);

[0211] acrylamides such as acrylamide, N-alkylacrylamide (the alkylgroup is an alkyl group having from 1 to 10 carbon atoms, such as methylgroup, ethyl group, propyl group, butyl group, tert-butyl group, heptylgroup, octyl group, cyclohexyl group, benzyl group and hydroxyethylgroup), N-arylacrylamide (the aryl group is, for example, a phenylgroup, a tolyl group, a nitrophenyl group, a naphthyl group, acyanophenyl group, a hydroxyphenyl group or a carboxyphenyl group),N,N-dialkylacrylamide (the alkyl group is an alkyl group having from 1to 10 carbon atoms, such as methyl group, ethyl group, butyl group,isobutyl group, ethylhexyl group and cyclohexyl group),N,N-diarylacrylamide (the aryl group is, for example, a phenyl group),N-methyl-N-phenylacrylamide, N-hydroxyethyl-N-methylacrylamide andN-2-acetamidoethyl-N-acetylacrylamide;

[0212] methacrylamides such as methacrylamide, N-alkylmethacrylamide(the alkyl group is an alkyl group having from 1 to 10 carbon atoms,such as methyl group, ethyl group, tert-butyl group, ethylhexyl group,hydroxyethyl group and cyclohexyl group), N-arylmethacrylamide (the arylgroup is, for example, a phenyl group), N,N-dialkylmethacrylamide (thealkyl group is, for example, an ethyl group, a propyl group or a butylgroup), N,N-diarylmethacrylamide (the aryl group is, for example, aphenyl group) and N-hydroxyethyl-N-methylmethacrylamide; allyl compoundssuch as allyl ester (e.g., allyl acetate, allyl caproate, allyl caprate,allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allylacetoacetate, allyl lactate) and allyloxy ethanol;

[0213] vinyl ethers such as alkyl vinyl ether (e.g., hexyl vinyl ether,octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether,methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinylether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinylether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether,dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether,butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfurylvinyl ether) and vinyl aryl ether (e.g., vinyl phenyl ether, vinyl tolylether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether, vinylnaphthyl ether, vinyl anthranyl ether);

[0214] vinyl esters such as vinyl butyrate, vinyl isobutyrate, vinyltrimethyl acetate, vinyl diethyl acetate, vinyl valerate, vinylcaproate, vinyl chloroacetate, vinyl dichloroacetate, vinylmethoxyacetate, vinyl butoxyacetate, vinyl phenylacetate, vinylacetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylchlorohexylcarboxylate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate,vinyl tetrachlorobenzoate and vinyl naphthoate;

[0215] styrenes such as styrene, alkylstyrene (e.g., methylstyrene,dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene,isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene,decylstyrene, benzylstyrene, chloromethylstyrene,trifluoromethylstyrene, ethoxymethylstyrene, acetoxymethylstyrene),alkoxystyrene (e.g., methoxystyrene, 4-methoxy-3-methylstyrene,dimethoxystyrene), halogen styrene (e.g., chlorostyrene,dichlorostyrene, trichlorostyrene, tetrachlorostyrene,pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene,fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene,4-fluoro-3-trifluoromethylstyrene), carboxystyrene and vinylnaphthalene; and

[0216] crotonic acid esters such as alkyl crotonate (e.g., butylcrotonate, hexyl crotonate, glycerin monocrotonate); dialkyl itaconates(e.g., dimethyl itaconate, diethyl itaconate, dibutyl itaconate);dialkyl esters of maleic acid or fumaric acid (e.g., dimethyl maleate,dibutyl fumarate), maleic anhydride, maleimide, acrylonitrile,methacrylonitrile and maleylonitrile. In addition,addition-polymerizable unsaturated compounds which can be copolymerizedin general may be used.

[0217] Specific examples of the repeating structural units representedby formulae (I) to (X) are set forth below, however, the presentinvention is not limited thereto.

[0218] Specific examples of the repeating structural units representedby formulae (XI) to (XIII) are set forth below, however, the presentinvention is not limited thereto.

[0219] Specific examples of the repeating structural units representedby formulae (XVI) to (XVII) are set forth below, however, the presentinvention is not limited thereto.

[0220] Specific examples of the repeating structural unit represented byformula (IA) are set forth below, however, the present invention is notlimited thereto.

[0221] Specific examples of the repeating structural unit represented byformula (IIA) are set forth below, however, the present invention is notlimited thereto.

[0222] In addition, specific examples of the repeating unit representedby formula (IIA) include (F-40) to (F-45) shown above.

[0223] Specific examples of the repeating structural unit represented byformula (VIA) are set forth below, however, the present invention is notlimited thereto.

[0224] In addition, specific examples of the repeating structural unitrepresented by formula (VIA) include (F-29) to (F-38) and (F-47) to(F-54) shown above.

[0225] Specific examples of the repeating structural unit represented byformula (IIIA) are set forth below, however, the present invention isnot limited thereto.

[0226] Specific examples of the repeating structural unit represented byformula (VIIA) are set forth below, however, the present invention isnot limited thereto.

[0227] These specific examples of the repeating structural units may beused individually or as a mixture of a plurality of those units.

[0228] The resin (A) having the above-described repeating structuralunits preferably has a weight average molecular weight of 1,000 to200,000, more preferably from 3,000 to 20,000. The molecular weightdistribution is from 1 to 10, preferably from 1 to 3, more preferablyfrom 1 to 2. As the molecular weight distribution is narrower, theresolution is higher, the resist shape is excellent, the side wall ofthe resist pattern is smoother and the roughness property is superior.

[0229] The amount added of the resin (A) for use in the presentinvention is, based on the solid content of the composition, generallyfrom 50 to 99.5% by weight, preferably from 60 to 98% by weight, morepreferably from 65 to 95% by weight.

[0230] [2] Compound (B) Capable of Generating Acid Upon Irradiation WithActinic Rays or Radiation of the Present Invention

[0231] Examples of the compound capable of decomposing upon irradiationwith actinic rays or radiation to generate an acid, which is used in thepresent invention, include a photoinitiator for photocationicpolymerization, a photoinitiator for photoradical polymerization, aphoto-decoloring agent for dyes, a photo-discoloring agent and acompound capable of generating an acid upon irradiation with known lightused for microresist and the like (for example, ultraviolet or farultraviolet ray of 200 to 400 nm, preferably g line, h line, i line anda KrF excimer laser ray) or with an ArF excimer laser ray, an electronbeam, an X ray, a molecular beam or an ion beam. The compound may beappropriately selected from these and a combination thereof.

[0232] Other examples of the compound capable of generating an acid uponirradiation with actinic rays or radiation for use in the presentinvention include onium salts such as diazonium salts described in S. I.Schlesinger, Photoqr. Sci. Enq., 18, 387 (1974), T. S. Bal et al.,Polymer, 21, 423 (1980), etc., ammonium salts described in U.S. Pat.Nos. 4,069,055, 4,069,056 and Re27,992, JP-A-3-140140 (the term “JP-A”as used herein means an “unexamined published Japanese patentapplication”), etc., phosphonium salts described in D. C. Necker et al.,Macromolecules, 17, 2468 (1984), C. S. Wen et al., Teh, Proc. Conf. Rad.Curing ASIA, p. 478, Tokyo, Oct. (1988), U.S. Pat. Nos. 4,069,055 and4,069,056, etc., iodonium salts described in J. V. Crivello et al.,Macromolecules, 10 (6) 1307 (1977), Chem. & Eng. News, Nov. 28, p. 31(1988), European Patents 104,143, 339,049 and 410,201, JP-A-2-150848,JP-A-2-296514, etc., sulfonium salts described in J. V. Crivello et al.,Polymer J., 17, 73 (1985), J. V. Crivello et al., J. Org. Chem., 43,3055 (1978), W. R. Watt et al., J. Polymer Sci., Polymer Chem. Ed., 22,1789 (1984), J. V. Crivello et al., Polymer Bull., 14, 279 (1985), J. V.Crivello et al., Macromolecules, 14 (5), 1141 (1981), J. V. Crivello etal., J. Polymer Sci., Polymer Chem. Ed., 17, 2877 (1979), EuropeanPatents 370,693, 161,811, 410,201, 339,049, 233,567, 297,443 and297,442, U.S. Pat. Nos. 4,933,377, 3,902,114, 4,760,013, 4,734,444 and2,833,827, German Patent 2,904,626, 3,604,580 and 3,604,581, etc.,selenonium salts described in J. V. Crivello et al., Macromolecules, 10(6), 1307 (1977), J. V. Crivello et al., J. Polymer Sci., Polymer Chem.Ed., 17, 1047 (1979), etc., and arsonium salts described in C. S. Wen etal., Teh, Proc. Conf. Rad. Curing ASIA, p. 478, Tokyo, October (1988),etc.; organic halogen compounds described in U.S. Pat. No. 3,905,815,JP-B-46-4605 (the term “JP-B” as used herein means an “examined Japanesepatent publication”), JP-A-48-36281, JP-A-55-32070, JP-A-60-239736,JP-A-61-169835, JP-A-61-169837, JP-A-62-58241, JP-A-62-212401,JP-A-63-70243, JP-A-63-298339, etc.; organic metals/organic halidesdescribed in K. Meier et al., J. Rad. Curing, 13 (4), 26 (1986), T. P.Gill et al., Inorg. Chem., 19, 3007 (1980), D. Astruc, Acc. Chem. Res.,19 (12), 377 (1896), JP-A-2-161445, etc.; photo-acid generators havingan O-nitrobenzyl type protective group described in S. Hayase et al., J.Polymer Sci., 25, 753 (1987), E. Reichmanis et al., J. Polymer Sci.,Polymer Chem. Ed., 23, 1 (1985), Q. Q. Zhu et al., J. Photochem., 36,85, 39, 317 (1987), B. Amit et al., Tetrahedron Lett., (24) 2205 (1973),D. H. R. Barton et al., J. Chem. Soc., 3571 (1965), P. M. Collins etal., J. Chem. Soc., Perkin I, 1695 (1975), M. Rudinstein et al.,Tetrahedron Lett., (17), 1445 (1975), J. W. Walker et al., J. Am. Chem.Soc., 110, 7170 (1988), S. C. Busman et al., J. Imaging Technol., 11(4), 191 (1985), H. M. Houlihan et al., Macromolecules, 21, 2001 (1988),P. M. Collins et al., J. Chem. Soc., Chem. Commun., 532 (1972), S.Hayase et al., Macromolecules, 18, 1799 (1985), E. Reichmanis et al., J.Electrochem. Soc., Solid State Sci. Technol., 130 (6), F. M. Houlihan etal., Macromolecules, 21, 2001 (1988), European Patents 0,290,750,046,083, 156,535, 271,851 and 0,388,343, U.S. Pat. Nos. 3,901,710 and4,181,531, JP-A-60-198538, JP-A-53-133022, etc.; compounds which arephotochemically decomposed to generate a sulfonic acid, represented byiminosulfonate, described in M. TUNOOKA et al., Polymer Preprints Japan,35 (8), G. Berner et al., J. Rad. Curing, 13 (4), W. J. Mijs et al.,Coating Technol., 55 (697), 45 (1983), Akzo, H. Adachi et al., PolymerPreprints, Japan, 37 (3), European Patents 0,199,672, 84,515, 044,115,618,564 and 0,101,122, U.S. Pat. Nos. 4,371,605 and 4,431,774,JP-A-64-18143, JP-A-2-245756, JP-A-3-140109, etc.; and disulfonecompounds described in JP-A-61-166544.

[0233] In addition, compounds in which the above-described group orcompound capable of generating an acid upon irradiation with actinicrays or radiation is introduced into the main chain or side chain of apolymer may also be used and examples thereof include the compoundsdescribed in M. E. Woodhouse et al., J. Am. Chem. Soc., 104, 5586(1982), S. P. Pappas et al., J. Imaging Sci., 30 (5), 218 (1986), S.Kondo et al., Makromol. Chem., Rapid Commun., 9, 625 (1988), Y. Yamadaet al., Makromol. Chem., 152, 153, 163 (1972), J. V. Crivello et al., J.Polymer Sci., Polymer Chem. Ed., 17, 3845 (1979), U.S. Pat. No.3,849,137, German Patent 3,914,407, JP-A-63-26653, JP-A-55-164824,JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853,JP-A-63-146029, etc.

[0234] Furthermore, the compounds capable of generating an acid uponirradiation with light, described in V. N. R. Pillai, Synthesis, (1), 1(1980), A. Abad et al., Tetrahedron Lett., (47) 4555 (1971), D. H. R.Barton et al., J. Chem. Soc., (C), 329 (1970), U.S. Pat. No. 3,779,778,European Patent 126,712, etc. may also be used.

[0235] Among these compounds capable of decomposing upon irradiationwith actinic rays or radiation to generate an acid, particularlyeffective compounds are described below.

[0236] (1) Oxazole derivative represented by the following formula(PAG1) and S-triazine derivative represented by formula (PAG2), whichare each substituted by trihalomethyl group:

[0237] wherein R²⁰¹ represents a substituted or unsubstituted aryl groupor a substituted or unsubstituted alkenyl group, R²⁰² represents asubstituted or unsubstituted aryl group, a substituted or unsubstitutedalkenyl group, a substituted or unsubstituted alkyl group or —C(Y)₃, andY represents a chlorine atom or a bromine atom.

[0238] Specific examples thereof include the following compounds,however, the present invention is not limited thereto.

[0239] (2) Iodonium salt represented by the following formula (PAG3) andsulfonium salt represented by formula (PAG4):

[0240] In formula (PAG3), Ar¹ and Ar² each independently represents asubstituted or unsubstituted aryl group. The substituent is preferablyan alkyl group, a haloalkyl group, a cycloalkyl group, an aryl group, analkoxy group, a nitro group, a carboxyl group, an alkoxycarbonyl group,a hydroxy group, a mercapto group or a halogen atom.

[0241] In formula (PAG4), R²⁰³, R²⁰⁴ and R²⁰⁵ each independentlyrepresents a substituted or unsubstituted alkyl group or a substitutedor unsubstituted aryl group, and preferably an aryl group having from 6to 14 carbon atoms, an alkyl group having from 1 to 8 carbon atoms or asubstituted derivative thereof. The substituent of the aryl group ispreferably an alkoxy group having from 1 to 8 carbon atoms, an alkylgroup having from 1 to 8 carbon atoms, a cycloalkyl group, a nitrogroup, a carboxyl group, a mercapto group, a hydroxy group or a halogenatom, and the substituent of the alkyl group is preferably an alkoxygroup having from 1 to 8 carbon atoms, a carboxyl group or analkoxycarbonyl group.

[0242] In formulae (PAG3) and (PAG4), Z⁻ represents an anion andspecific examples thereof include alkyl sulfonate anion, cycloalkylsulfonate anion, perfluoroalkyl sulfonate anion and aryl sulfonate anion(e.g., benzenesulfonate anion, naphthalene sulfonate anion andanthracene sulfonate, which may have a substituent).

[0243] Two of R²⁰³, R²⁰⁴ and R²⁰⁵, or Ar¹ and Ar² may be combinedthrough a single bond or a substituent.

[0244] Specific examples thereof include the following compounds,however, the present invention is not limited thereto.

[0245] The above-mentioned onium salts represented by formulae (PAG3)and (PAG4) are known and can be synthesized by the method described, forexample, in J. W. Knapczyk et al., J. Am. Chem. Soc., 91, 145 (1969), A.L. Maycok et al., J. Org. Chem., 35, 2532 (1970), E. Goethas et al.,Bull. Soc. Chem. Belg., 73, 546 (1964), H. M. Leicester, J. Ame. Chem.Soc., 51, 3587 (1929), J. V. Crivello et al., J. Polym. Chem. Ed., 18,2677 (1980), U.S. Pat. Nos. 2,807,648 and 4,247,473, JP-A-53-101331,etc.

[0246] (3) Disulfone derivative represented by the following formula(PAG5) and iminosulfonate derivative represented by formula (PAG6):

[0247] wherein Ar³ and Ar⁴ each independently represents a substitutedor unsubstituted aryl group, R²⁰⁶ represents a substituted orunsubstituted alkyl group or a substituted or unsubstituted aryl group,and A represents a substituted or unsubstituted alkylene group, asubstituted or unsubstituted alkenylene group or a substituted orunsubstituted arylene group.

[0248] Specific examples thereof include the following compounds,however, the present invention is not limited thereto.

[0249] (4) Diazodisulfone derivative compound represented by thefollowing formula (PAG7)

[0250] wherein R represents a linear, branched or cyclic alkyl group oran aryl group which may be substituted.

[0251] Specific examples thereof include the following compounds,however, the present invention is not limited thereto.

[0252] In the positive resist composition of the present invention, thecompound (B) preferably comprises at least one compound selected fromsulfonium salt and iodonium salt compounds capable of generating atleast one of acids (i) to (iii) below upon irradiation with one of anactinic ray and radiation:

[0253] (i) a perfluoroalkylsulfonic acid having 2 or more carbon atoms;

[0254] (ii) a perfluoroarylsulfonic acid; and

[0255] (iii) an arylsulfonic acid having a perfluoroalkyl group as asubstituent.

[0256] The iodonium salt and sulfonium salt compounds as the preferablecompound (B) more preferably is represented by the (PAG3) or (PAG4)respectively, wherein X⁻ represents an anion of any one of the acids (i)to (iii).

[0257] The amount added of the compound (B) capable of generating anacid upon irradiation with actinic rays or radiation, which is used inthe present invention, is from 0.1 to 20% by weight, preferably from 0.5to 10% by weight, more preferably from 1 to 7% by weight, based on theentire solid content of the composition of the present invention. Thesecompounds may be used individually or as a mixture of a plurality of thecompounds.

[0258] [3] Surfactant (C) of the Present Invention (Fluorine-Containingand/or Silicon-Containing Surfactant)

[0259] The positive photoresist composition of the present inventioncontains a fluorine-containing and/or silicon-containing surfactant (C).More specifically, the positive photoresist composition of the presentinvention contains any one of a fluorine-containing surfactant, asilicon-containing surfactant and a surfactant containing both afluorine atom and a silicon atom, or contains two or more thereof. Bythe addition of this fluorine-containing and/or silicon-containingsurfactant, the development defect is prevented and the coatability isimproved.

[0260] Examples of these surfactants include surfactants described inJP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950,JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988and U.S. Pat. Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330,5,436,098, 5,576,143, 5,296,143, 5,294,511 and 5,824,451. The followingcommercially available surfactants each may also be used as it is.

[0261] Examples of the commercially available surfactant which can beused include fluorine-containing surfactants and silicon-containingsurfactants, such as EFtop EF301, EF303 and EF352 (produced byShin-Akita Kasei K. K.), Florad FC430 and 431 (produced by Sumitomo 3 MInc.), Megafac F171, F173, F176, F189 and R08 (produced by Dainippon Ink& Chemicals, Inc.), Asahi Guard AG710, Surflon S-382, SC101, 102, 103,104, 105 and 106 (produced by Asahi Glass Co., Ltd.), and Troysol S-366(produced by Troy Chemical). In addition, polysiloxane polymer KP-341(produced by Shin-Etsu Chemical Co., Ltd.) may also be used as asilicon-containing surfactant.

[0262] The amount of the surfactant blended is usually from 0.001 to 2%by weight, preferably from 0.01 to 1% by weight, based on the solidcontent in the composition of the present invention. These surfactantsmay be added individually or in combination of two or more thereof.

[0263] [4] Acid Diffusion Inhibitor (D) of the Present Invention

[0264] The composition of the present invention preferably contains anacid diffusion inhibitor for the purpose of preventing fluctuation inperformance (e.g., T-top shape formation of pattern, fluctuation insensitivity, fluctuation in line width of pattern) with the passage oftime after the irradiation with actinic rays or radiation until theheat-treatment, fluctuation due to aging after the coating, or excessdiffusion of acid (deterioration of resolution) at the time ofheat-treatment after the irradiation with actinic rays or radiation. Theacid diffusion inhibitor is an organic basic compound, for example, anorganic basic compound containing a basic nitrogen, and a compound wherethe conjugate acid has a pKa value of 4 or more is preferably used.

[0265] Specific examples thereof include a compound having the followingstructures (A) to (E):

[0266] wherein R²⁵⁰, R²⁵¹ and R²⁵², which may be identical or different,each represents a hydrogen atom, an alkyl group having from 1 to 6carbon atoms, an aminoalkyl group having from 1 to 6 carbon atoms, ahydroxyalkyl group having from 1 to 6 carbon atoms or a substituted orunsubstituted aryl group having from 6 to 20 carbon atoms, provided thatR²⁵¹ and R²⁵² may combine with each other to form a ring, and

[0267] R²⁵³, R²⁵⁴, R²⁵⁵ and R²⁵⁶, which may be identical or different,each represents an alkyl group having from 1 to 6 carbon atoms.

[0268] The compound is more preferably a nitrogen-containing basiccompound having two or more nitrogen atoms different in the chemicalenvironment within one molecule, still more preferably a compound havingboth a substituted or unsubstituted amino group and a ring structurecontaining a nitrogen atom, or a compound having an alkylamino group.

[0269] Specific preferred examples thereof include a substituted orunsubstituted guanidine, a substituted or unsubstituted aminopyridine, asubstituted or unsubstituted aminoalkylpyridine, a substituted orunsubstituted aminopyrrolidine, a substituted or unsubstituted indazole,an imidazole, a substituted or unsubstituted pyrazole, a substituted orunsubstituted pyrazine, an substituted or unsubstituted pyrimidine, asubstituted or unsubstituted purine, a substituted or unsubstitutedimidazoline, a substituted or unsubstituted pyrazoline, a substituted orunsubstituted piperazine, a substituted or unsubstituted aminomorpholineand a substituted or unsubstituted aminoalkylmorpholine. The substituentis preferably an amino group, an aminoalkyl group, an alkylamino group,an aminoaryl group, an arylamino group, an alkyl group, an alkoxy group,an acyl group, an acyloxy group, an aryl group, an aryloxy group, anitro group, a hydroxyl group or a cyano group.

[0270] More preferred compounds are guanidine, 1,1-dimethylguanidine,1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole,4-methylimidazole, N-methylimidazole, 2-phenylimidazole,4,5-diphenylimidazole, 2,4,5-triphenylimidazole, 2-aminopyridine,3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine,4-dimethyl-aminopyridine, 2-diethylaminopyridine,2-(aminomethyl)-pyridine, 2-amino-3-methylpyridine,2-amino-4-methylpyridine, 2-amino-5-methylpyridine,2-amino-6-methylpyridine, 3-aminoethylpyridine, 4-aminoethylpyridine,3-aminopyrrolidine, piperazine, N-(2-aminoethyl)piperazine,N-(2-aminoethyl)piperidine, 4-amino-2,2,6,6-tetramethyl-piperidine,4-piperidinopiperidine, 2-iminopiperidine, 1-(2-aminoethyl)pyrrolidine,pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole,pyrazine, 2-(aminomethyl)-5-methylpyrazine, pyrimidine,2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline,3-pyrazoline, N-aminomorpholine and N-(2-aminoethyl)morpholine.

[0271] These nitrogen-containing basic compounds are used individuallyor in combination of two or more thereof.

[0272] The ratio between the acid generator and the organic basiccompound used in the composition is preferably 2.5 to 300 {(acidgenerator)/(organic basic compound) (by mol)}. If this molar ratio isless than 2.5, low sensitivity results and the resolution may decreasein some cases, whereas if it exceeds 300, the thickening of the patternincreases in aging after the exposure until the heat-treatment and theresolution sometimes decreases. The (acid generator)/(organic basiccompound) (by mol) is preferably from 5.0 to 200, more preferably from7.0 to 150.

[0273] [5] Other Components Used In the Composition of the PresentInvention

[0274] (1) Solvents

[0275] The composition of the present invention is dissolved in asolvent which can dissolve the above-described respective components,and then coated on a substrate. The solvent used here is preferablyethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone,γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether,ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycolmonoethyl ether acetate, propylene glycol monomethyl ether, propyleneglycol monoethyl ether, propylene glycol monomethyl ether acetate,toluene, ethyl acetate, methyl lactate, ethyl lactate, methylmethoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethylpyruvate, propyl pyruvate, N,N-dimethylformamide, dimethyl sulfoxide,N-methylpyrrolidone or tetrahydrofuran. These solvents are usedindividually or in combination.

[0276] For forming a pattern on a resist film, for example, in theproduction of a precision integrated circuit device, the positivephotoresist composition of the present invention is coated on asubstrate (e.g., transparent substrate such as silicon/silicon dioxidecoating, glass substrate and ITO substrate), irradiated with actinicrays or radiation using a drawing apparatus, heated, developed, rinsedand dried, whereby a good resist pattern can be formed.

[0277] The developer which can be used for the positive resistcomposition of the present invention is an aqueous solution of an alkalisuch as inorganic alkalis (e.g., sodium hydroxide, potassium hydroxide,sodium carbonate, sodium silicate, sodium metasilicate, aqueousammonia), primary amines (e.g., ethylamine, n-propylamine), secondaryamines (e.g., diethylamine, di-n-butylamine), tertiary amines (e.g.,triethylamine, methyldiethylamine), alcohol amines (e.g.,dimethylethanolamine, triethanolamine), quaternary ammonium salts (e.g.,tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline) orcyclic amines (e.g., pyrrole, piperidine). This aqueous alkali solutionmay be used after adding thereto an appropriate amount of an alcohol(e.g., isopropyl alcohol) or surfactant (e.g., nonionic surfactant).

[0278] Among these developers, preferred are quaternary ammonium salts,more preferred are tetramethylammonium hydroxide and choline.

[0279] The present invention is described in greater detail below,however, the present invention should not be construed as being limitedthereto.

SYNTHESIS EXAMPLE 1

[0280] A 150-ml 1,1,2-trichloro-trifluoroethylene solution containing9.4 g (0.10 mol) of norbornene and 19.4 g (0.10 mol) of tert-butylnorbornene-2-carbonate was charged into a 1 L-volume autoclave and apressure was applied to 200 psi in a nitrogen atmosphere. Furthermore,20 g (0.20 mol) of tetrafluoroethylene was injected and heated at 50° C.while stirring. To the reaction solution, a 15-ml1,1,2-trichloro-trifluoroethylene solution containing 1.2 g ofdi(4-tert-butylcyclohexyl)peroxydicarbonate was injected over 20 minutesand the solution was continuously stirred for 20 hours. After thecompletion of reaction, the reaction solution was charged into 2 L ofmethanol while vigorously stirring to precipitate a white resin. Theprecipitated resin was separated by filtration and dried in a vacuum toobtain 23.5 g of Resin (1) of the present invention.

[0281] By the GPC measurement, the molecular weight of Resin (1) was66200 as a weight average (Mw). Also, the composition of Resin (1) wasexamined by the C¹³—NMR measurement and found to be Structure(F-1)/norbornene/(B-16)=45/30/25 by mol.

SYNTHESIS EXAMPLE 2

[0282] 14.3 g (0.04 mol) of Monomer (a) shown below, 3.9 g (0.04 mol) ofmaleic anhydride and 2.6 g (0.02 mol) of tert-butyl acrylate weredissolved in 100 ml of MEK and heated at 70° C. in a nitrogen stream.Thereto, 0.2 g of V-601 (produced by Wako Pure Chemical Industries,Ltd.) was added as a polymerization initiator and the solution wasstirred for 3 hours. Then, 0.2 g of V-601 was added and the solution wascontinuously stirred for 4 hours. Thereafter, the reaction solution wascharged into 1 L of tert-butyl methyl ether while vigorously stirring toprecipitate a white resin. The precipitated resin was separated byfiltration and dried in a vacuum to obtain 12.1 g of Resin (2) of thepresent invention.

[0283] By the GPC measurement, the molecular weight of Resin (2) was8,900 as a weight average (Mw). Also, the composition of Resin (2) wasexamined by the C¹³—NMR measurement and found to be Structure(F-21)/maleic anhydride/(B-4)=39/38/23 by mol.

SYNTHESIS EXAMPLE 3

[0284] 6.7 g (0.015 mol) of Monomer (b) shown below, 1.4 g (0.006 mol)of 2-methyl-2-adamantane methacrylate and 1.8 g 1(0.009 mol) ofmevalonic lactone methacrylate were dissolved in 30 ml of1-methoxy-2-propanol and thereto, 0.1 g of2,2′-azobis(2,4-dimethylvaleronitrile) (V-65, trade name, produced byWako Pure Chemical Industries, Ltd.) as a polymerization initiator and a70-ml 1-methoxy-2-propanol solution containing 15.6 g (0.035 mol) ofMonomer (b), 3.3 g (0.014 mol) of 2-methyl-2-adamantane methacrylate and4.2 g (0.021 mol) of mevalonic lactone methacrylate were added dropwiseover 2 hours at 70° C. while stirring in a nitrogen stream. After 2hours, 0.1 g of the initiator was additionally added and the reactionwas further allowed to proceed for 2 hours. Thereafter, the temperaturewas elevated to 90° C. and the stirring was continued for 1 hour. Thereaction solution was allowed to cool and then charged into 1 L of ionexchanged water/methanol (1/1) while vigorously stirring to precipitatea white resin. The obtained resin was dried under reduced pressure toobtain 15.8 g of Resin (3) of the present invention.

[0285] By the GPC measurement, the molecular weight was 10,200 as aweight average (Mw). Also, the composition of Resin (3) was examined bythe C¹³—NMR measurement and found to be Structure(F-30)/(B-7)/(B-11)=48/21/31 by mol.

SYNTHESIS EXAMPLES 4 TO 12

[0286] The resins (A) of the present invention shown in Table 1 belowwere synthesized in the same manner as above. TABLE 1 Synthesis of Resin(A) of the Invention Resin Composition Molecular (A) (structural unitand molar ratio in resin) Weight  (4) (F-1)/(B-20)/(B-23) = 45/25/305,800  (5) (F-1)/(F-21)/(B-16) = 48/33/19 4,500  (6) (F-22)/maleicanhydricle/(B-8) = 42/39/19 8,700  (7) (F-30)/(F-48)/(B-2) = 42/17/4112,600  (8) (F-50)/(B-7)/(B-11) = 31/35/34 9,200  (9) (F-55)/maleicanhydride/(B-4) = 40/37/23 7,400 (10) (F-16)/maleic anhydride/(B-8) =43/34/23 6,300 (11) (F-26)/maleic anhydride/(B-12) = 40/33/27 8,900 (12)(F-31)/(F-42)/(B-8) = 44/18/38 11,600

SYNTHESIS EXAMPLE 13

[0287] A 150-ml 1,1,2-trichloro-trifluoroethylene solution containing9.4 g (0.10 mol) of norbornene and 35.8 g (0.10 mol) of Monomer (a)shown below was charged into a 1 L-volume autoclave and a pressure wasapplied to 200 psi in a nitrogen atmosphere. Furthermore, 20 g (0.20mol) of tetrafluoroethylene was injected and heated at 50° C. whilestirring. To the reaction solution, a 15-ml1,1,2-trichloro-trifluoroethylene solution containing 1.2 g ofdi(4-tert-butylcyclohexyl)peroxydicarbonate was injected over 20 minutesand the solution was continuously stirred for 20 hours. After thecompletion of reaction, the reaction solution was charged into 2 L ofmethanol while vigorously stirring to precipitate a white resin. Theprecipitated resin was separated by filtration and dried in a vacuum toobtain 37.4 g of Resin (13) of the present invention.

[0288] By the GPC measurement, the molecular weight of Resin (13) was8,800 as a weight average (Mw). Also, the composition of Resin (13) wasexamined by the C¹³—NMR measurement and found to be Structure(F-1)/(F-21)/norbornene=48/30/22 by mol.

SYNTHESIS EXAMPLE 14

[0289] 34.1 g of Resin (14) of the present invention was synthesized inthe same manner as in Synthesis Example 13 except for using 32.2 g (0.04mol) of Monomer (c) shown below in place of Monomer (a) used inSynthesis Example 13.

[0290] By the GPC measurement, the molecular weight of Resin (14) was7,400 as a weight average (Mw). Also, the composition of Resin (14) wasexamined by the C¹³—NMR measurement and found to be Structure(F-1)/(F-15)/norbornene=49/25/26 by mol.

SYNTHESIS EXAMPLES 15 TO 22

[0291] The resins (A) of the present invention shown in Table 2 belowwere synthesized in the same manner as above. TABLE 2 Synthesis of Resin(A) of the Invention Resin Composition Molecular (A) (structural unitand molar ratio in resin) Weight (15) (F-1)/(F-16)/norbornene = 45/26/298,700 (16) (F-1)/(F-20)/(B-4) = 48/30/22 9,300 (17) (F-2)/(F-22)/(B-4) =42/39/19 7,900 (18) (F-7)/(F-20)/norbornene = 35/33/32 6,400 (19)(F-12)/(F-21)/norbornene = 23/38/39 5,800 (20) (F-1)/(F-25)/(B-4) =48/23/29 7,200 (21) (F-1)/(F-16)/(B-16) = 44/26/40 9,500 (22)(F-1)/(F-15)/(B-16)/norbornene = 38/21/21/20 10,900

SYNTHESIS EXAMPLE 23

[0292] 14.3 g (0.04 mol) of Monomer (a) shown below, 3.9 g (0.04 mol) ofmaleic anhydride and 11.7 g (0.02 mol) of perfluorooctylethylnorbornene-2-carboxylate were dissolved in 100 ml of MEK and heated at70° C. in a nitrogen stream. Thereto, 0.2 g of V-601 (produced by WakoPure Chemical Industries, Ltd.) was added as a polymerization initiatorand the solution was stirred for 3 hours. Furthermore, 0.2 g of V-601was added and the solution was continuously stirred for 4 hours.Thereafter, the reaction solution was charged into 1 L of tert-butylmethyl ether while vigorously stirring to precipitate a white resin. Theprecipitated resin was separated by filtration and dried in a vacuum toobtain 16.2 g of Resin (23) of the present invention.

[0293] By the GPC measurement, the molecular weight of Resin (23) was8,700 as a weight average (Mw). Also, the composition of Resin (23) wasexamined by the C¹³—NMR measurement and found to be Structure(F-21)/(F-55)/maleic anhydride=42/18/40 by mol.

SYNTHESIS EXAMPLE 24

[0294] 6.7 g (0.015 mol) of Monomer (b) shown below, 2.7 g (0.005 mol)of perfluorooctylethyl methacrylate, 1.2 g (0.005 mol) of2-methyl-2-adamantane methacrylate and 1.0 g (0.005 mol) of mevaloniclactone methacrylate were dissolved in 30 ml of 1-methoxy-2-propanol andthereto, 0.1 g of 2,2′-azobis(2,4-dimethylvaleronitrile) (V-65, tradename, produced by Wako Pure Chemical Industries, Ltd.) as apolymerization initiator and a 70-ml 1-methoxy-2-propanol solutioncontaining 15.6 g (0.035 mol) of Monomer (b), 6.4 g (0.012 mol) ofperfluorooctylethyl methacrylate, 2.8 g (0.012 mol) of2-methyl-2-adamantane methacrylate and 2.4 g (0.012 mol) of mevaloniclactone methacrylate were added dropwise over 2 hours at 70° C. whilestirring in a nitrogen stream. After 2 hours, 0.1 g of the initiator wasadditionally added and the reaction was further allowed to proceed for 2hours. Thereafter, the temperature was elevated to 90° C. and thestirring was continued for 1 hour. The reaction solution was allowed tocool and then charged into 1 L of ion exchanged water/methanol (1/1)while vigorously stirring to precipitate a white resin. The obtainedresin was dried under reduced pressure to obtain 21.5 g of Resin (24) ofthe present invention.

[0295] By the GPC measurement, the molecular weight was 10,500 as aweight average (Mw). Also, the composition of Resin (24) was examined bythe C¹³—NMR measurement and found to be Structure(F-30)/(F-48)/(B-7)/(B-11)=48/15/18/19 by mol.

SYNTHESIS EXAMPLES 25 To 32

[0296] The resins (A) of the present invention shown in Table 3 belowwere synthesized in the same manner as above. TABLE 3 Synthesis of Resin(A) of the Invention Resin Composition Molecular (A) (structural unitand molar ratio in resin) Weight (25) (F-15)/(F-58)/maleic anhydride =30/24/46 9,700 (26) (F-16)/(F-55)/(B-4)/maleic anhydride = 26/14/22/3810,600 (27) (F-21)/(F-60)/(B-4)/maleic anhydride = 28/14/21/37 8,500(28) (F-21)/(F-64)/maleic anhydride = 37/23/40 9,400 (29)(F-25)/(F-55)/(B-4)/maleic anhydride = 21/18/25/36 7,800 (30)(F-30)/(F-50)/(B-2)/(B-12) = 45/16/15/24 10,400 (31)(F-30)/(F-53)/(B-8)/(B-11) = 40/18/25/17 9,700 (32)(F-30)/(F-54)/(B-7)/(B-13) = 38/15/31/16 9,900

SYNTHESIS EXAMPLE 33

[0297] 13.5 g (0.05 mol) of4-[bis(trifluoromethyl)hydroxy-methyl]styrene and 3.4 g (0.05 mol) ofmethacrylonitrile were dissolved in 100 ml of N,N-dimethylacetamide andheated at 70° C. in a nitrogen stream. Thereto, 0.1 g of2,2′-azobis(2,4-dimethylvaleronitrile) (V-65, trade name, produced byWako Pure Chemical Industries, Ltd.) was added as a polymerizationinitiator and the solution was stirred for 3 hours. Then, 0.1 g of V-65was additionally added and the stirring was continued for 4 hours.Thereafter, the reaction solution was charged into 1 L ofmethanol/tert-butyl methyl ether while vigorously stirring toprecipitate a white resin. The precipitated resin was separated byfiltration, dried in a vacuum and dissolved in 100 ml of THF. Thereto,2.9 g (0.04 mol) of ethyl vinyl ether was added and a catalytic amountof p-toluenesulfonic acid was added. The resulting solution was stirredat room temperature for 8 hours. The reaction was stopped by addingtriethylamine in an amount 2 times the p-toluenesulfonic acid catalystand the reaction solution was charged into 3 L of ultrapure water whilevigorously stirring. The precipitated resin was separated by filtrationand dried to obtain 14.1 g of Resin (33) of the present invention.

[0298] By the GPC measurement, the molecular weight of Resin (33) was10,900 as a weight average (Mw). Also, the composition of Resin (33) wasexamined by the C¹³-NMR measurement and found to be Structure(F-39)/(F-42)/(C-10)=16/36/48 by mol.

SYNTHESIS EXAMPLES 34 TO 40

[0299] The resins (A) of the present invention shown in Table 4 belowwere synthesized in the same manner as above. TABLE 4 Synthesis of Resin(A) of the Invention Resin Composition Molecular (A) (structural unitand molar ratio in resin) Weight (34) (F-39)/(F-41)/(C-10) = 14/38/4811,100 (35) (F-44)/(C-10) = 53/47 9,800 (36) (F-42)/(C-12) = 55/4510,700 (37) (F-39)/(F-43)/(C-10) = 13/39/48 12,600 (38)(F-1)/(F-21)/(C-5) = 40/35/25 6,800 (39) (F-19)/maleic anhydride/(C-8) =35/33/32 8,300 (40) (F-1)/(B-4)/(C-8) = 43/34/23 7,400

SYNTHESIS EXAMPLES 41 TO 68

[0300] Synthesis of Resin (42)

[0301] Into a 100 ml-volume three neck flask equipped with a reflux tubeand a nitrogen inlet tube, 4-(2-hydroxy-hexafluoroisopropyl)styrene(produced by Central Glass Co., Ltd.) and 4-(1-methoxyethoxy)styrene(produced by Toso) were charged at a molar ratio of 50/50. Thereafter,tetrahydrofuran was added to prepare 30 g in total of a reactionsolution having a monomer concentration of 30% by weight. This solutionwas stirred and heated to 65° C. in a nitrogen stream and thereto, anazo-type polymerization initiator V-65 (produced by Wako Pure ChemicalIndustries, Ltd.) was added in an amount of 5.0 mol % based on the totalmolar number of those two monomers and reacted for 8 hours whilestirring in a nitrogen stream. To the obtained reaction solution, 200 mlof hexane was added and the produced polymer was precipitated from thesolution and purified by separating unreacted monomers. The polymercomposition determined by C¹³NMR was 49/51.

[0302] The obtained polymer was analyzed by GPC (in THF solution,calculated in terms of standard polystyrene), as a result, the weightaverage molecular weight was 10,200, the dispersion degree was 2.20 andthe percentage of resins having a molecular weight of 1,000 or lesscontained in the polymer was 15% by weight.

[0303] The resins (A) of the present invention shown in Table 5 belowwere synthesized in the same manner as above. TABLE 5 Resin CompositionMolecular (A) (structural unit and molar ratio in resin) Weight (41)(II-1)/(A-1) = 48/52 8,900 (42) (II-1)/(A-2) = 49/51 10,200 (43)(II-1)/(A-3′) = 53/47 5,800 (44) (II-1)/(A-10) = 61/39 9,200 (45)(II-1)/(A-19) = 64/36 8,500 (46) (II-1)/(A-34) = 60/40 8,600 (47)(II-1)/(A-35) = 51/49 8,800 (48) (II-1)/(A-36) = 50/50 8,400 (49)(II-2)/(A-19) = 64/36 10,100 (50) (II-1′)/(A-20) = 61/39 9,200 (51)(II-1″)/(A-26) = 55/45 9,100 (52) (II-3)/(A-26) = 49/51 7,800 (53)(II-4)/(A-26) = 52/48 12,100 (54) (II-1)/(B-1) = 58/42 14,200 (55)(II-1)/(B-1′) = 70/30 16,600 (56) (II-1)/(B-7) = 78/22 9,200 (57)(II-1)/(B-8) = 73/27 8,400 (58) (II-1)/(B-12′) = 69/31 8,600 (59)(II-1)/(A-19)/(VII-2) = 64/26/10 9,200 (60) (II-1)/(A-19)/(F-1) =63/27/9 8,900 (61) (II-1)/(A-19)/(III-1) = 60/33/7 9,000 (62)(II-1)/(A-19)/(F-7) = 58/33/9 9,500 (63) (II-1)/(A-19)/(F-19) = 51/33/1610,200 (64) (II-1)/(B-4)/(VII-2) = 61/24/15 10,600 (65)(II-1)/(B-12″)/(F-2) = 59/33/8 10,000 (66) (II-1)/(B-10)/(III-3) =56/30/14 7,200 (67) (II-3)/(B-8)/(F-7) = 49/36/15 9,200 (68)(II-4)/(B-12′)/(F-24) = 59/33/8 8,300

EXAMPLE 1

[0304] Measurement of Transmittance

[0305] 1.36 g of each resin synthesized above and 0.04 g oftriphenylsulfonium nonaflate salt were dissolved in 8.5 g of propyleneglycol monomethyl ether acetate and thereto, 0.005 g ofdicyclohexylmethylamine and as a surfactant, 0.01 g of Megafac R₀₈(produced by Dainippon Ink & Chemicals Inc.) were added to prepareresist compositions of the present invention.

[0306] Each sample solution was filtered through a 0.1-μm Teflon filter,coated on a calcium fluoride disk using a spin coater and dried underheating at 120° C. for 5 hours to obtain a resist film having a filmthickness of 0.1 μm. The absorption of the coating film was measured byActon CAMS-507 spectrometer and the transmittance at 157 nm wascalculated.

[0307] The results are shown in Tables 6 and 7. TABLE 6 Resin of theTransmittance Invention at 157 nm (%)  (1) 58  (2) 52  (3) 53  (4) 56 (5) 63  (6) 51  (7) 68  (8) 52  (9) 51 (10) 55 (11) 50 (12) 49 (13) 66(14) 60 (15) 61 (16) 63 (17) 65 (18) 60 (19) 60 (20) 64 (21) 58 (22) 58(23) 58 (24) 57 (25) 59 (26) 53 (27) 55 (28) 60 (29) 52 (30) 59 (31) 58(32) 56 (33) 48 (35) 46 (37) 47 (39) 51 (40) 53

[0308] TABLE 7 Transmittance Resin at 157 nm (%) (41) 55 (42) 48 (43) 52(44) 53 (45) 50 (46) 49 (47) 47 (48) 45 (49) 51 (50) 50 (51) 49 (52) 47(53) 45 (54) 51 (55) 50 (56) 47 (57) 48 (58) 49 (59) 51 (60) 58 (61) 57(62) 56 (63) 52 (64) 51 (65) 55 (66) 58 (67) 51 (68) 49 ComparativeExample 1 18 (commercially available acetal-type resist for KrF)

[0309] As seen from the results in Tables 6 and 7, the measuredtransmittance of the coating film using the composition of the presentinvention is almost in excess of 50% and this reveals that the coatingfilm has a sufficiently high transmittance at 157 nm.

EXAMPLE 2

[0310] Evaluation of Coatability and Development Defect

[0311] The resist compositions of the present invention were prepared bychanging the surfactant used in Example 1 to the following W-1 to W-4.The surfactant used is shown in Tables 8 and 9.

[0312] The surfactants used are:

[0313] W1: Megafac F176 (produced by Dainippon Ink & Chemicals Inc.)(containing fluorine)

[0314] W2: Megafac R08 (produced by Dainippon Ink & Chemicals Inc.)(containing fluorine and silicon)

[0315] W3: Polysiloxane polymer KP-341 (produced by Shin-Etsu ChemicalCo., Ltd.

[0316] W4: Polyoxyethylene nonylphenyl ether

[0317] Each sample solution was filtered through a 0.1-μm Teflon filter,coated on a silicon wafer treated with hexamethyldisilazane using a spincoater and dried under heating on a vacuum contact-type hot plate at110° C. for 90 seconds to obtain resist films having a film thickness of0.3 μm. The obtained resist films each was imagewise exposed using a KrFexcimer stepper (FPA-3000EX5) manufactured by Canon, after-heated at110° C. for 90 seconds and then developed with a 0.262 N TMAH aqueoussolution to form a 0.5-μm L/S pattern.

[0318] The development defect and coatability were evaluated as follows.

[0319] Number of Development Defects

[0320] The resist pattern obtained above was measured on the number ofdevelopment defects using a machine KLA-2112 manufactured by KLA Tencholand the obtained primary data value was used as the number ofdevelopment defects.

[0321] Coatability (In-Plane Uniformity)

[0322] Each resist solution was coated on a 8-inch silicon wafer andtreated in the same manner as in the above-described formation of resistlayer to obtain a resist coating film for the measurement of in-planeuniformity. The film thickness of this coating film was measured usingLambda A manufactured by Dainippon Ink & Chemicals Inc. at 36 sites tomake a cross at equal intervals along the diameter direction of thewafer.

[0323] From the measured values, a standard deviation was determined.When the triple of the standard deviation is less than 50, the ratingwas O and when 50 or more, X.

[0324] The results in the evaluation of performance are shown in Tables8 and 9. TABLE 8 Resin (A) of Surfactant Development the Invention UsedDefects Coatability  (1) W-1 25 ◯  (2) W-2 21 ◯  (3) W-2 28 ◯  (4) W-330 ◯  (5) W-1 27 ◯  (6) W-2 22 ◯  (7) W-3 26 ◯  (8) W-3 35 ◯  (9) W-2 32◯ (10) W-2 25 ◯ (11) W-1 29 ◯ (12) W-2 24 ◯ (13) W-1 25 ◯ (14) W-2 22 ◯(15) W-2 23 ◯ (16) W-3 28 ◯ (17) W-3 26 ◯ (18) W-1 25 ◯ (19) W-2 21 ◯(20) W-3 26 ◯ (21) W-2 24 ◯ (22) W-2 25 ◯ (23) W-2 29 ◯ (24) W-2 30 ◯(25) W-3 27 ◯ (26) W-1 24 ◯ (27) W-1 26 ◯ (28) W-3 31 ◯ (29) W-2 25 ◯(30) W-2 30 ◯ (31) W-3 29 ◯ (32) W-1 28 ◯ (33) W-1 20 ◯ (35) W-2 22 ◯(37) W-2 24 ◯ (39) W-3 27 ◯ (40) W-1 25 ◯

[0325] TABLE 9 Resin (A) of Surfactant Development the Invention UsedDefects Coatability (41) W-1 24 ◯ (42) W-2 28 ◯ (43) W-1 25 ◯ (44) W-124 ◯ (45) W-2 26 ◯ (46) W-1 25 ◯ (47) W-3 25 ◯ (48) W-1 24 ◯ (49) W-2 22◯ (50) W-1 26 ◯ (51) W-1 24 ◯ (52) W-1 30 ◯ (53) W-3 24 ◯ (54) W-1 29 ◯(55) W-2 24 ◯ (56) W-1 26 ◯ (57) W-3 22 ◯ (58) W-1 24 ◯ (59) W-2 20 ◯(60) W-1 24 ◯ (61) W-3 25 ◯ (62) W-1 24 ◯ (63) W-2 27 ◯ (64) W-1 29 ◯(65) W-1 24 ◯ (66) W-2 21 ◯ (67) W-1 21 ◯ (68) W-1 24 ◯ (1) (ComparativeNone 2000 X Example 2) (1) (Comparative W-4 650 X Example 3)

[0326] As seen from the results in Tables 8 and 9, the composition ofthe present invention containing a fluorine and/or silicon-containingsurfactant has far excellent coatability as compared with ComparativeExamples and also, is greatly reduced in the number of developmentdefects.

EXAMPLE 3

[0327] Evaluation of Image-Forming Property

[0328] Using Resins (1) to (5), (13), (15), (17), (23), (25), (27),(33), (35), (40) and (41) to (68) of the present invention, resistsolutions were prepared in the same manner as in Example 1.

[0329] Each sample solution was filtered through a 0.1-μm Teflon filter,coated on a silicon wafer treated with hexamethyldisilazane using a spincoater and dried under heating on a vacuum contact-type hot plate at110° C. for 90 seconds to obtain resist films having a film thickness of0.1 μm. The obtained resist films each was measured on the dissolutioncontrast between the exposed area and the unexposed area upon exposureat 157 nm using a 157-nm laser exposure/dissolution behavior analyzerVUVES-4500 (manufactured by Lisotec Japan).

[0330] The results are shown in Tables 10 and 11. TABLE 10 Resin of theDissolution Invention Contrast (tanθ)  (1) 5.8  (2) 6.5  (3) 6.2  (4)5.6  (5) 5.9 (13) 6.2 (15) 6.9 (17) 6.5 (23) 6.4 (25) 5.7 (27) 6.1 (33)6.3 (35) 6.5 (40) 6.6

[0331] TABLE 11 Resin Dissolution Contrast (tanθ) (41) 5.8 (42) 5.7 (43)6.1 (44) 5.9 (45) 6.3 (46) 5.4 (47) 5.9 (48) 6.1 (49) 5.8 (50) 5.5 (51)5.6 (52) 5.8 (53) 5.8 (54) 6.2 (55) 5.9 (56) 5.8 (57) 6.1 (58) 5.8 (59)5.8 (60) 5.8 (61) 5.8 (62) 6.1 (63) 6.3 (64) 6.1 (65) 6.2 (66) 5.8 (67)6.1 (68) 6.1 Comparative Example 4  5.3^(*1)) (commercially availableacetal-type resist for KrF)

[0332] As seen from the results in Tables 10 and 11, the composition ofthe present invention provides a dissolution contrast, namely,image-forming property equal to that provided by the resist practicallyused for KrF excimer of Comparative Example.

[0333] According to the present invention, a positive resist compositionexhibiting sufficiently high transmittance and image-forming propertyeven with light at a short wavelength of 157 nm, ensuring excellentsensitivity and resolution, and improved in the problems of coatabilityand development defect ascribable to fluorine resin can be provided.

[0334] While the invention has been described in detail and withreference to specific embodiments thereof, it will be apparent to oneskilled in the art that various changes and modifications can be madetherein without departing from the spirit and scope thereof.

What is claimed is:
 1. A positive resist composition comprising: (A) afluorine group-containing resin having: a structure wherein at least oneof the main chain and the side chain of the polymer skeleton has atleast one fluorine atom; and a group capable of decomposing under theaction of an acid to increase the solubility in an alkali developer; (B)a compound capable of generating an acid upon irradiation with at leastone of an actinic ray or radiation; and (C) a surfactant containing atleast one of a silicon atom and fluorine atom.
 2. The positive resistcomposition as claimed in claim 1, wherein the resin (A) comprises atleast one of fluorine group-containing resins (i) and (ii) below: (iii)a fluorine group-containing resin having at least one selected from aperfluoroalkylene group and a perfluoroarylene group as a part or all ofthe main chain of the polymer skeleton; (iv) a fluorine group-containingresin having at least one selected from a perfluoroalkyl group, aperfluoroaryl group, a hexafluoro-2-propanol group and a group whereinthe OH group in a hexafluoro-2-propanol group is protected, as a part orall of the side chain of the polymer skeleton.
 3. The positive resistcomposition as claimed in claim 1, wherein the resin (A) contains atleast one of repeating units represented by formulae (I) to (X):

wherein R₀ and R₁ each represents a hydrogen atom, a fluorine atom, oran alkyl, perfluoroalkyl, cycloalkyl or aryl group, each of which mayhave a substituent; R₂ to R₄ each represents an alkyl, perfluoroalkyl,cycloalkyl or aryl group, each of which may have a substituent and R₀and R₁ may combine to form a ring, R₀ and R₂ may combine to form a ringand R₃ and R₄ may combine to form a ring; R₅ represents a hydrogen atom,an alkyl, perfluoroalkyl, monocyclic or polycyclic cycloalkyl, acyl oralkoxycarbonyl group, each of which may have a substituent; R₆, R₇ andR₈ each represents a hydrogen atom, a halogen atom or an alkyl,perfluoroalkyl or alkoxy group, each of which may have a substituent; R₉and R₁₀ each represents a hydrogen atom, a halogen atom, a cyano group,or an alkyl or haloalkyl group, each of which may have a substituent;R₁₁ and R₁₂ each represents a hydrogen atom, a hydroxyl group, a halogenatom a cyano group, an alkoxy group, an acyl group, an alkyl,cycloalkyl, alkenyl, aralkyl or aryl group, and the alkyl, thecycloalkyl, the alkenyl, the aralkyl or the aryl group each may have asubstituent; R₁₃ and R₁₄ each represents a hydrogen atom, a halogenatom, a cyano group, or an alkyl or haloalkyl, each of which may have asubstituent; R₁₅ represents an alkyl, monocyclic or polycycliccycloalkyl, alkenyl, aralkyl or aryl group, each of which has a fluorineatom; R₁₆, R₁₇ and R₁₈ each represents a hydrogen atom, a halogen atom,a cyano group, or an alkyl, perfluoroalkyl, alkoxy or —CO—O—R₁₅ group,each of which may have a substituent; R₁₉, R₂₀ and R₂₁ each represents ahydrogen atom, a fluorine atom or an alkyl, monocyclic or polycycliccycloalkyl, alkenyl, aralkyl, aryl or alkoxy group, each of which has afluorine atom, provided that at least one of R₁₉, R₂₀ and R₂₁ is a groupother than a hydrogen atom; A₁ and A₂ each represents a single bond, adivalent alkylene, alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—,—CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene,cycloalkylene or arylene group each may have a substituent; R₂₂, R₂₃ andR₂₅ each represents a single bond or a divalent alkylene, alkenylene,cycloalkylene or arylene group, each of which may have an ether group,an ester group, an amide group, a urethane group or a ureido group; R₂₄represents a hydrogen atom or an alkyl, cycloalkyl, aralkyl or arylgroup, each of which may have a substituent; n represents 0 or 1; and x,y and z each represents an integer of 0 to
 4. 4. The positive resistcomposition as claimed in claim 1, wherein the resin (A) contains atleast one of repeating units represented by formulae (XI) to (XIII):

wherein R₂₆, R₂₇ and R₃₂ each represents a hydrogen atom, a halogenatom, a cyano group, or an alkyl or haloalkyl group, each of which mayhave a substituent; R₂₈ and R₃₃ each represents —C(R₃₆)(R₃₇)(R₃₈),—C(R₃₆)(R₃₇)(OR₃₉) or a group represented by formula (XIV):

wherein R₂₉, R₃₀ and R₃₁ each represents a hydrogen atom, a halogenatom, a cyano group or an alkyl, perfluoroalkyl, alkoxy or —CO—O—R₂₈group, each of which may have a substituent; R₃₄ and R₃₅ each representsa hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, analkoxy group, an acyl group, an alkyl, cycloalkylene, alkenyl, aralkylor aryl group, and the alkyl, cycloalkylene, alkenyl, aralkyl or arylgroup each may have a substituent; R₃₆, R₃₇, R₃₈ and R₃₉ each representsan alkyl, cycloalkyl, alkenyl, aralkyl or aryl group, each of which mayhave a substituent, and two of R₃₆, R₃₇ and R₃₈, or two of R₃₆, R₃₇ andR₃₉ may combine to form a ring; R₄₀ represents an alkyl, cycloalkyl,alkenyl, alkynyl, aralkyl or aryl group, each of which may have asubstituent; A₃ and A₄ each represents a single bond, a divalentalkylene, alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—,—CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene,cycloalkylene or arylene group, each of which may have a substituent;R₂₂ to R₂₅ have the same meanings as above; Z represents an atomic groupconstituting a monocyclic or polycyclic alicyclic group together withthe carbon atom; and n represents 0 or
 1. 5. The positive composition asclaimed in claim 1, wherein the resin (A) contains at least one ofrepeating units represented by formulae (XV) to (XVII):

wherein R₄₁ represents an alkyl, cycloalkyl, aralkyl or aryl group, eachof which may have a substituent; R₄₂ represents a hydrogen atom, ahalogen atom, a cyano group, or an alkyl or haloalkyl group, each ofwhich may have a substituent; A₅ represents a single bond, a divalentalkylene, alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—,—CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene,cycloalkylene or arylene group each may have a substituent; R₂₂ to R₂₅have the same meanings as above.
 6. The positive resist composition asclaimed in claim 1, wherein the resin (A) contains: at least one ofrepeating units represented by formulae (I) to (III); and at least oneof repeating units represented by formulae (IV) to (VI):

wherein R₀ and R₁ each represents a hydrogen atom, a fluorine atom or analkyl, perfluoroalkyl, cycloalkyl or aryl group, each of which may havea substituent, R₂ to R₄ each represents an alkyl, perfluoroalkyl,cycloalkyl or aryl group, each of which may have a substituent, and R₀and R₁ may combine to form a ring, R₀ and R₂ may combine to form a ring,and R₃ and R₄ may combine to form a ring; R₅ represents a hydrogen atomor an alkyl, perfluoroalkyl, monocyclic or polycyclic cycloalkyl, acylor alkoxycarbonyl group, each of which may have a substituent; R₆, R₇and R₈ each represents a hydrogen atom, a halogen atom or an alkyl,perfluoroalkyl or alkoxy group, each of which may have a substituent; R₉represents a hydrogen atom, a halogen atom, a cyano group, or an alkylor haloalkyl group, each of which may have a substituent; A₁ and A₂ eachrepresents a single bond, a divalent alkylene, alkenylene,cycloalkylene, arylene group, —O—CO—R₂₂—, —CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—,and the divalent alkylene, alkenylene, cycloalkylene or arylene groupeach may have a substituent; R₂₂, R₂₃ and R₂₅ each represents a singlebond or a divalent alkylene, alkenylene, cycloalkylene or arylene group,each of which may have an ether group, an ester group, an amide group, aurethane or a ureido group; R₂₄ represents a hydrogen atom or an alkyl,cycloalkyl, aralkyl or aryl group, each of which may have a substituent;and n represents 0 or
 1. 7. The positive resist composition as claimedin claim 1, wherein the resin (A) contains: at least one of repeatingunits represented by formulae (IV) to (VI) below; and at least one ofrepeating units represented by formulae (VIII) to (X) below:

wherein R₅ represents a hydrogen atom or an alkyl, perfluoroalkyl,monocyclic or polycyclic cycloalkyl, acyl or alkoxycarbonyl group, eachof which may have a substituent; R₆, R₇ and R₈ each represents ahydrogen atom, a halogen atom or an alkyl, perfluoroalkyl or alkoxygroup, each of which may have a substituent; R₉ represents a hydrogenatom, a halogen atom, a cyano group, or an alkyl or haloalkyl group,each of which may have a substituent; R₁₃ and R₁₄ each represents ahydrogen atom, a halogen atom, a cyano group, or an alkyl or haloalkylgroup, each of which may have a substituent; R₁₅ represents an alkyl,monocyclic or polycyclic cycloalkyl, alkenyl, aralkyl or aryl group,each of which has a fluorine atom; R₁₆, R₁₇ and R₁₈ each represents ahydrogen atom, a halogen atom, a cyano group, or an alkyl,perfluoroalkyl, alkoxy or —CO—O—R₁₅ group, each of which may have asubstituent; R₁₉, R₂₀ and R₂₁ each represents a hydrogen atom, afluorine atom or an alkyl, monocyclic or polycyclic cycloalkyl, alkenyl,aralkyl, aryl or alkoxy group, each of which has a fluorine atom,provided that at least one of R₁₉, R₂₀ and R₂₁ is a group other than ahydrogen atom; A₁ and A₂ each represents a single bond, a divalentalkylene, alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—,—CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene,cycloalkylene or arylene group each may have a substituent; R₂₂, R₂₃ andR₂₅ each represents a single bond or a divalent alkylene, alkenylene,cycloalkylene or arylene group, each of which may have an ether group,an ester group, an amide group, a urethane group or a ureido group; R₂₄represents a hydrogen atom or an alkyl, cycloalkyl, aralkyl or arylgroup, each of which may have a substituent; n represents 0 or 1; and x,y and z each represents an integer of 0 to
 4. 8. The positive resistcomposition as claimed in claim 1, wherein the resin (A) contains: atleast one of repeating units represented by formulae (IV) to (VII)below; and at least one of repeating units represented by formulae (XV)to (XVII) below:

wherein R₅ represents a hydrogen atom or an alkyl, perfluoroalkyl,monocyclic or polycyclic cycloalkyl, acyl or alkoxycarbonyl group, eachof which may have a substituent; R₆, R₇ and R₈ each represents ahydrogen atom, a halogen atom, or an alkyl, perfluoroalkyl or alkoxygroup, each of which may have a substituent; R₉ and R₁₀ each representsa hydrogen atom, a halogen atom, a cyano group, or an alkyl or haloalkylgroup, each of which may have a substituent; R₁₁ and R₁₂ each representsa hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, analkoxy group, an acyl group, an alkyl, cycloalkyl, alkenyl, aralkyl oraryl group, and the alkyl, cycloalkyl, alkenyl, aralkyl or aryl groupeach may have a substituent; A₁ and A₂ each represents a single bond ora divalent alkylene, alkenylene, cycloalkylene, arylene group,—O—CO—R₂₂—, —CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—, and the divalent alkylene,alkenylene, cycloalkylene or arylene group each may have a substituent;R₂₂, R₂₃ and R₂₅ each represents a single bond or a divalent alkylene,alkenylene, cycloalkylene or arylene group, each of which may have anether group, an ester group, an amide group, a urethane group or aureido group; R₂₄ represents a hydrogen atom or an alkyl, cycloalkyl,aralkyl or aryl group, each of which may have a substituent; nrepresents 0 or 1; R₄₁ represents an alkyl, cycloalkyl, aralkyl or arylgroup, each of which may have a substituent; R₄₂ represents a hydrogenatom, a halogen atom, a cyano group, or an alkyl or haloalkyl group,each of which may have a substituent; and A₅ represents a single bond, adivalent alkylene, alkenylene, cycloalkylene, arylene group, —O—CO—R₂₂—,—CO—O—R₂₃— or —CO—N(R₂₄)—R₂₅—, and the divalent alkylene, alkenylene,cycloalkylene or arylene group each may have a substituent.
 9. Thepositive resist composition as claimed in claim 1, wherein the resin (A)contains: at least one of repeating units represented by formula (IA)below; and at least one of repeating units represented by formula (IIA)below:

wherein R_(1a) and R_(5a) each represents a hydrogen atom, a halogenatom, a cyano group or an alkyl group which may have a substituent;R_(2a), R_(3a), R_(6a) and R_(7a) each represents a hydrogen atom, a Acehalogen atom, a cyano group, a hydroxyl group or an alkyl, cycloalkyl,alkoxy, acyl, acyloxy, alkenyl, aryl or aralkyl group, each of which mayhave a substituent; R_(50a) to R_(55a) each represents a hydrogen atom,a fluorine atom or an alkyl group which may have a substituent, and atleast one of R_(50a) to R_(55a) represents a fluorine atom or an alkylgroup where at least one hydrogen atom is substituted by a fluorineatom; R_(56a) represents a hydrogen atom or an alkyl, cycloalkyl, acylor alkoxycarbonyl group, each of which may have a substituent; R_(4a)represents a group represented by formula (IVA) or (VA):

 wherein in formula (IVA), R_(11a), R_(12a) and R_(13a) each representsan alkyl, cycloalkyl, alkenyl, aralkyl or aryl group, each of which mayhave a substituent; and in formula (VA), R_(14a) and R_(15a) eachrepresents a hydrogen atom or an alkyl group which may have asubstituent; and R_(16a) represents an alkyl, cycloalkyl, aralkyl oraryl group, each of which may have a substituent, and two of R_(14a) toR_(16a) may combine to form a ring.
 10. The positive resist compositionas claimed in claim 1, wherein the resin (A) contains: at least one ofrepeating units represented by formula (IIA) below; and at least one ofrepeating units represented by (VIA) below:

wherein in formula (IIA), R_(5a) represents a hydrogen atom, a halogenatom, a cyano group or an alkyl group which may have a substituent;R_(6a) and R_(7a) each represents a hydrogen atom, a halogen atom, acyano group, a hydroxyl, or an alkyl, cycloalkyl, alkoxy, acyl, acyloxy,alkenyl, aryl or aralkyl group, each of which may have a substituent;R_(50a) to R_(55a) each represents a hydrogen atom, a fluorine atom oran alkyl group which may have a substituent, and at least one of R_(50a)to R_(55a) represents a fluorine atom or an alkyl group where at leastone hydrogen atom is substituted by a fluorine atom; R_(56a) representsa hydrogen atom or an alkyl, cycloalkyl, acyl or alkoxycarbonyl group,each of which may have a substituent; in formula (VIA), R_(17a1) andR_(17a2) each represents a hydrogen atom, a halogen atom, a cyano groupor an alkyl group which may have a substituent; R_(18a) represents—C(R_(18a1))(R_(18a2))(R_(18a3)) or —C(R_(18a1))(R_(18a2))(OR_(18a4));R_(18a1) to R_(18a4) each represents a hydrogen atom or an alkyl,cycloalkyl, alkenyl, aralkyl or aryl group, each of which may have asubstituent, and two of R_(18a1), R_(18a2) and R_(18a3) or two ofR_(18a1), R_(18a2) and R_(18a4) may combine to form a ring; and A₀represents a single bond or a divalent linking group which may have asubstituent.
 11. The positive resist composition as claimed in claim 10,wherein in formula (VIA), R_(18a) is a group represented by formula(VIA-A):

wherein R_(18a5) and R_(18a6) each represents an alkyl group which mayhave a substituent; and R_(18a7) represents a cycloalkyl group which mayhave a substituent.
 12. The positive resist composition as claimed inclaim 10, wherein in formula (VIA), R_(18a) is a group represented byformula (VIA-B):

wherein R_(18a8) represents an alkyl, alkenyl, alkynyl, aralkyl or arylgroup, each of which may have a substituent.
 13. The positive resistcomposition as claimed in claim 9, wherein at least one of R_(1a) informula (IA) and R_(5a) in formula (IIA) is a trifluoromethyl group. 14.The positive resist composition as claimed in claim 10, wherein at leastone of R_(5a) in formula (IIA) and R_(17a2) in formula (VIA) is atrifluoromethyl group.
 15. The positive resist composition as claimed inclaims 9, wherein the resin (A) further contains at least one ofrepeating units represented by formulae (IIIA) and (VIIA):

wherein in formula (IIIA), R_(8a) represents a hydrogen atom, a halogenatom, a cyano group or an alkyl group which may have a substituent;R_(9a) and R_(10a) each represents a hydrogen atom, a halogen atom, acyano group or an alkyl, cycloalkyl, alkoxy, acyl, acyloxy, alkenyl,aryl or aralkyl group, each of which may have a substituent; and informula (VIIA), R_(19a) and R_(20a) each represents a hydrogen atom, ahalogen atom, a cyano group or an alkyl group which may have asubstituent, R_(21a) represents a hydrogen atom, a halogen atom, analkyl which may have a substituent or —A₁—CN group; and A₁ represents asingle bond or a divalent linking group.
 16. The positive resistcomposition as claimed in claim 10, wherein the resin (A) furthercontains at least one of repeating units represented by formulae (IIIA)and (VIIA):

wherein in formula (IIIA), R_(8a) represents a hydrogen atom, a halogenatom, a cyano group or an alkyl group which may have a substituent;R_(9a) and R_(10a) each represents a hydrogen atom, a halogen atom, acyano group or an alkyl, cycloalkyl, alkoxy, acyl, acyloxy, alkenyl,aryl or aralkyl group, each of which may have a substituent; and informula (VIIA), R_(19a) and R_(20a) each represents a hydrogen atom, ahalogen atom, a cyano group or an alkyl group which may have asubstituent, R_(21a) represents a hydrogen atom, a halogen atom, analkyl which may have a substituent or —A₁—CN group; and Al represents asingle bond or a divalent linking group.
 17. The positive resistcomposition as claimed in claim 1, which further comprises a compoundcontaining a basic nitrogen atom.
 18. The positive resist composition asclaimed in claim 1, wherein the compound (B) comprises at least onecompound selected from sulfonium salt and iodonium salt compoundscapable of generating at least one of acids (i) to (iii) below uponirradiation with one of an actinic ray and radiation: (i) aperfluoroalkylsulfonic acid having 2 or more carbon atoms; (ii) aperfluoroarylsulfonic acid; and (iii) an arylsulfonic acid having aperfluoroalkyl group as a substituent.
 19. The positive resistcomposition as claimed in claim 1, which is a composition to beirradiated with an ultraviolet ray having a wave length of 160 nm orless.
 20. The positive resist composition as claimed in claim 19,wherein the ultraviolet ray is F₂ excimer laser ray having a wave lengthof 157 nm.